This study was conducted to provide reference for rational fertilization and agrochemical application in cucumber plantation,and relieve the problem of environmental pollution and vegetable agrochemical residues. The ...This study was conducted to provide reference for rational fertilization and agrochemical application in cucumber plantation,and relieve the problem of environmental pollution and vegetable agrochemical residues. The effects of different combinations of fertilization and agrochemical application on cucumber yield and cost input were investigated. Four treatments were conducted,including T1( conventional fertilization + conventional agrochemical application,CK),T2( conventional fertilization + recommended agrochemical application),T3( recommended fertilization + conventional agrochemical application) and T4( recommended fertilization + recommended agrochemical application). The results showed that T4 had fewer kinds of fertilizers and agrochemicals than that of T1,and had a yield increasing effect on cucumber,and the yield increase was 7 003. 5 kg/hm^2,with an increasing rate of 19. 25%; and it also had obvious cost-saving and benefit-increasing effects,specifically,the cost was saved by 10 941 yuan/hm^2 and the benefit was increased by 31 951. 5 yuan/hm^2. The results of this experiment were satisfactory,and higher benefit was obtained with lower input. This study will provide reference for cucumber planter to choose fertilizers and agrochemicals,and lays a foundation for alleviating the ecological soil problems.展开更多
The objective of this study was to determine the morphology mechanism of nitrogen (N) fertilizer rates and ratio on lodging resistance through analying its effects among lodging index (LI), lodging-related morphol...The objective of this study was to determine the morphology mechanism of nitrogen (N) fertilizer rates and ratio on lodging resistance through analying its effects among lodging index (LI), lodging-related morphological traits and physical strength in basal intemodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels (0, 150 and 300 kg ha-L) and two ratios of basal to topdressing (8:2 and 5:5) with two super rice cultivars (Yliangyou 2 and Wuyunjing 23), were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal intemodes and culm's physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was significant greater than that of Wuyunjing 23 due to larger bending moment by whole plant (WP) with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no significant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength (M) in basal intemodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress (BS) of Wuyunjing 23 and section modulus (Z) of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction ofBS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, influencing their M indirectly. These results suggested that breaking strength was the key factor influencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of japonica super rice influenced breaking strength, as well as lodging index, respectively.展开更多
A pot experiment was conducted to study the effects of different nitrogen application time (during the tillering or the booting stages) with the same nitrogen rates on the caryopsis development and grain quality of ...A pot experiment was conducted to study the effects of different nitrogen application time (during the tillering or the booting stages) with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6. The increased nitrogen fertilizer (urea), especially applied during the booting stage, could evidently increase the milled rice rate, head rice rate and protein content in rice grains compared with the control (no nitrogen application), and decrease chalky grain rate and amylose content. Moreover, the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages, especially during the booting stage. During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents, but not obviously for the amylopectin content in rice grain. Increased topdressing of nitrogen fertilizer, especially applied during the booting stage, had significant effect on the development and structures of amyloplasts and proteinoplasts. That is, it could change the distribution, number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen, Compared with the control the arrangements of amyloplasts and proteinoplasts were closer, with more numbers, higher density and less interspaces each ohter. Furthermore, most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.展开更多
Agricultural chemical use has caused a public concern over environmental issue while decisions about applying chemicals are made by individual farmers. The critical decision-making role of farmers relative to agricult...Agricultural chemical use has caused a public concern over environmental issue while decisions about applying chemicals are made by individual farmers. The critical decision-making role of farmers relative to agricultural chemical use creates a need for accurate information on their perceptions of various chemical-related hazards and the factors that may influence such judgments. Based on data collected from 177 land operators at Xinxiang County in Henan Province of China, an empirical analysis is conducted to examine the relationship between farmers' character and the behavior of fertilizer application. Study findings reveal that: the characteristics of household head and household, and the nature of farming management positively affect the amount of fertilizers applied; information on fertilizers and the knowledge about environmental impact of fertilizer application have negative impacts by contrast. To formulate effective pollution control policies at the farm level, it is imperative for policy-makers to convey information to producers by demonstration projects, technical assistance, and education programs. Under a changed political environment, some combination of education and economic incentives could be lower cost and more effective tools for achieving desired environmental conservative goals.展开更多
Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied. The experiments on long-term application of K fertiliz...Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied. The experiments on long-term application of K fertilizer and wheat straw to soil in Hebei fluvo aquic soil and Shanxi brown soil in northern China were begun in 1992. The results showed that K fertilizer and straw could improve the yields of wheat and maize with the order of NPK + St 〉 NPK 〉 NP + St 〉 NP, and treatment of K fertilizer made a significant difference to NP, and the efficiency of K fertilizer in maize was higher than in wheat under rotation system of Hebei. In contrast with Shanxi, the wastage of soil potassium was a more serious issue in the rotation system in Hebei, only treatment of NPK + St showed a surplus of potassium and the others showed a wane. K fertilizer and straw could improve the content of water-soluble K, nonspecifically adsorbed K, non-exchangeable K, mineral K, and total K in contrast to NP; however, K fertilizer and straw reduce the proportion of mineral K and improve proportion of other forms of potassium in the two locating sites. Compared with the beginning of orientation, temporal variability character of soil K content and proportion showed a difference between the two soil types; furthermore, there was a decrease in the content of mineral K and total K simultaneously in the two locating sites. As a whole, the effect of K fertilizer applied to soil directly excelled to wheat straw to soil. Wheat straw to soil was an effective measure to complement potassium to increase crop yield and retard the decrease of soil K.展开更多
The hyperaccumulator Sedum alfredii Hance(S.alfredii)may be employed for zinc(Zn)and cadmium(Cd)-polluted soil remediation.However,the low phytoremediation efficiency,related to the low biomass production,limits its u...The hyperaccumulator Sedum alfredii Hance(S.alfredii)may be employed for zinc(Zn)and cadmium(Cd)-polluted soil remediation.However,the low phytoremediation efficiency,related to the low biomass production,limits its use with that purpose.In this experiment,nitrogen(N),phosphorus(P),and potassium(K)fertilizers,and organic manure were applied to investigate the phytoremediation ability of S.alfredii.Hydroponic and pot experiments were conducted using Zn-Cd polluted soil.The hydroponic experiment indicated that appropriate fertilizer application could increase(p<0.05)the amount of accumulated Zn and Cd in S.alfredii.When N supply ranged from 0.5 to 2.5 mmol L^(−1),it could improve growth and accumulation of Zn and Cd in whole plants of S.alfredii.The 1 mmol L^(−1) N was an optimal N dosage for shoot biomass production and Cd accumulation in shoots,while the 2.5 mmol L^(−1) was an optimal N dosage for Zn accumulation in shoots.Both low(<0.05 mmol L^(−1))and high(>0.8 mmol L^(−1))P supply decreased growth,and Zn/Cd accumulation in whole plants of the studied species.The 0.1 mmol L^(−1) P was an optimal dosage for S.alfredii biomass production and Zn/Cd accumulation in shoots.The supply levels within the range from 0.3 to 1 mmol L^(−1) K could significantly improve the biomass production of S.alfredii and its capability to accumulate Zn and Cd in the biomass.The 0.5 mmol L^(−1) K was an optimal dosage for the whole biomass production and Zn accumulation in shoots,while the 1 mmol L^(−1) was an optimal K dosage for Zn accumulation in shoots,which was 17.2%higher than the control.Moreover,the soil pot experiment showed that the combination of organic(fermented manure)and inorganic fertilizers made significant effects on the Zn and Cd-polluted soil remediation by S.alfredii.These effects varied,however,with the application of different proportions of N,P,K and organic matter.The Zn accumulation by S.alfredii reached the highest efficiency ability under the highest fertilizer mixing rate(N:50 mg kg^(−1),P:40 mg kg^(−1),K:100 mg kg^(−1),organic matter:1%).Even more,S.alfredii showed the strongest ability to accumulate Cd with a lower fertilizer mixing rate(N:25mg kg^(−1),P:20mg kg^(−1),K:50 mg kg^(−1),organic matter:0.5%).展开更多
By two years (2007-2008) located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, ...By two years (2007-2008) located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, Heilongjiang Province. The results showed that the combined application of organic and inorganic fertilizers could increase the organinc matter, alkaline nitrogen, available phosphorus and available potassium. At the same time, the increasing application of organic fertilizer could reduce the soil bulk density and improve the field moisture capacity. Field moisture capacity and organic matter of the combined application of high quantities of organic manure and inorganic fertilizers AtB5 treatment increased the fhstest, organic matter increased by 3.33 g. kg and field moisture capacity increased by 11.25% than the beginning of the experiment. Under the same fertilization, the combined application of organic and inorganic fertilizers' increasing production range was higher than the single chemical fertilizers' which was from 0.8% to 9.4%. The results showed that the combined application of organic and inorganic fertilizers could increase the nutrient contents of soil and also was the highest productivity contribution to black soil fertility. It was the best fertilization structure of increasing productivity level and improving the soil fertility.展开更多
The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effe...The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effect on crop. Five fertilizer treatments: no fertilizer (CK), nitrogen phosphorus fertilizer (NP), nitrogen potassium fertilizer (NK), phosphorus potassium (PK), and nitrogen phosphorus potassium fertilizer (NPK) were designed. Field experiment on the response of biomass dry weight and N, P, K, Cu, Zn, Fe, and Mn element distribution of stem, leaf and seed of maize (Zea mays L.) to different fertilizer treatments application was carried out. The results showed that dry weight and element content of various organs of maize were different. N content of various organs followed this order leaf〉 seed 〉 stem; P content of various organs was seed 〉 leaf〉 stem; K content was stem 〉 leaf〉 seed; and Fe content was leaf〉 stem 〉 seed. Fertilizer application reduced the differences of N, P, K, and Fe contents of various organs, and changed the size order of the dry weight and the Cu and Zn contents of leaf, seed and stem. Except for individual treatment, the response direction of N, P and Fe elements to fertilizer application was similar to Cu and Zn. The response of element content of various organs of maize to different fertilizer combinations was also different. The response extent of N, P and K major elements to fertilizer application was larger than microelement of Cu, Zn, Fe, and Mn; the response extent of stem and leaf was larger than seed; the response to NPK fertilizer treatment was bigger than NP, NK and PK. In the whole, response differences of element distribution to various fertilizer treatments were not remarkable. Besides, element distribution of various organs of maize was also influenced by the mutual effect of fertilizer varieties. The response direction and extent of various element distributions to different fertilizer treatments had both similarities and differences. Adjusting fertilizer application could change the biomass dry weight and element distribution of various organs of maize, thus promote the uptake and cycle of nutrient. This investigation could provide useful information for high production.展开更多
To find proper nitrogen fertilizer application mode of rapeseed( Brassica napus L.),promote the high and stable yield of rapeseed,field experiment was carried out to study the effect of nitrogen fertilizer application...To find proper nitrogen fertilizer application mode of rapeseed( Brassica napus L.),promote the high and stable yield of rapeseed,field experiment was carried out to study the effect of nitrogen fertilizer application modes on the yield and economic traits of Fengyou 10 rapeseed planted in two different fertility soils,and characteristics and differences of responses of different fertility soils to nitrogen fertilizer application modes were compared and analyzed. The results showed that the yield and related economic traits of rapeseed treated by nitrogen fertilizer were higher than the control group; in the nitrogen fertilizer treatment group,when the nitrogen fertilizer was applied as the base fertilizer and wintering fertilizer at the ratio of 7∶ 3,the rapeseed yield was higher than the control group and reached the highest; when the nitrogen fertilizer was applied as the base fertilizer,wintering fertilizer,and bud fertilizer at the ratio of 5∶ 3∶ 2,the rapeseed yield was significantly higher than the control group but was the lowest. These indicate that sufficient nitrogen supply is the basis for normal growth and development of rape seedlings. When the pure nitrogen fertilizer was at 192 kg/ha and the ratio of base fertilizer and wintering fertilizer was 7∶ 3,it can better coordinate the high yield of rapeseed and overall use of nitrogen fertilizer,and obtain higher rapeseed yield.展开更多
Most research-based fertilizer inputs proposed for small scale farmers to increase their productivity do not achieve the required results and should consider indigenous practices. This study evaluates the practices of...Most research-based fertilizer inputs proposed for small scale farmers to increase their productivity do not achieve the required results and should consider indigenous practices. This study evaluates the practices of nutrient fertilizer input by farmers and researchers and relates them to their corresponding yields and profit so as to establish the appropriateness of the practices in 13 districts of the Northern regions of Ghana. Soil nutrients assessment of Nitrogen (N), Phosphorus (P) and Potassium (K) contents used to evaluate the soil NPK status was based on previous studies. Data on fertilizer application by farmers and researchers were obtained from the Savanna Agricultural Research Institute (SARI). The amount of N, P and K fertilizer input in 13 Districts and its associated maize grain yields by both farmers (89) and researchers were calculated and compared using two-sample t-test. The t-test results indicated that average amount of fertilizer input by researchers was significantly (p < 0.05) higher than the average amount of fertilizer input by the smallholder farmers, but the high fertilizer input did not significantly (p = 0.74) increase researchers’ maize yields and profits in all 13 study districts grouped together, but there was maize increment in only eight districts. On the average, farmers from five districts applied low fertilizer and recorded low yields. However, when researchers increased quantities of fertilizer applied in these five districts, yield significantly (p < 0.05) increased. The outcome showed that smallholder farmers in these five districts could increase maize yields by 36% in the region should they adopt the maize production strategy by the researchers. The study concluded that, for best options, recommended fertilizer doses to enhance maize yields should consider district-specific farmers’ practices and soil NPK status. The study could enable better implementation of location-based nutrient recommendation in the Northern Region of Ghana.展开更多
This paper studied the effect of reducing application of chemical fertilizer,increasing application of functional organic fertilizer and trace elements and fully using biological pesticides on physiological traits,yie...This paper studied the effect of reducing application of chemical fertilizer,increasing application of functional organic fertilizer and trace elements and fully using biological pesticides on physiological traits,yield and quality of radish. The results showed that applying functional organic fertilizer and trace elements and fully using biological pesticides could help to significantly improve the radish fleshy root yield,increase soluble sugar and vitamin C content,reduce crude fiber and nitrate content,but had no significant influence on radish moisture content,glucosinolates and chlorpyrifos content in organophosphorus pesticides.展开更多
In order to provide a theoretical basis for apple cultivation techniques and to provide a reference for preparation of scientific management measures,the occurrence and damage status of apple little leaf in northern G...In order to provide a theoretical basis for apple cultivation techniques and to provide a reference for preparation of scientific management measures,the occurrence and damage status of apple little leaf in northern Guizhou was investigated,and fertilizer control test against the disease was also conducted.(1)Apple little leaf occurred from April to October in apple producing areas in northern Guizhou every year,with heavy incidence from April to May,light incidence from June to July,and the lightest incidence from August to October.(2) Effectiveness test showed that application of zinc sulfate fertilizer 135 g + cow dung 10 kg received the best control effect,followed by zinc sulfate fertilizer 165 g + cow dung 10 kg,then zinc sulfate fertilizer 105 g + cow dung 10 kg and zinc sulfate fertilizer 150 g + cow dung 10 kg.(3) Based on local environmental conditions,occurrence and damage situation,incidence conditions and fertilizer efficacy test,comprehensive prevention and control technology with rational supplement of zinc fertilizer could be used to control apple little leaf.展开更多
The response of rice to N fertilizer applicationhas shown that high rates of N application donot always ensure a proportional increase inyield due to high N losses. A model, ORYZA-0 was developed by ten Berge for desi...The response of rice to N fertilizer applicationhas shown that high rates of N application donot always ensure a proportional increase inyield due to high N losses. A model, ORYZA-0 was developed by ten Berge for designingoptimum N fertilizer management strategy inrice. We evaluated the performance ofORYZA-0 in Jinhua, Zhejiang Province. ORYZA-0 includes N uptakes, partition-ing of N among the organs, and utilization ofleaf N in converting solar energy to dry mat-ter. It can predict the amount and time of Nfertilizer application to achieve a maximumbiomass or yield combining with Price algo-rithm optimization procedure.展开更多
This paper summarized the requirements of organic agriculture for soil environment,fertilizer application and irrigation water quality,put forward safeguard measures for organic agriculture in terms of soil,fertilizer...This paper summarized the requirements of organic agriculture for soil environment,fertilizer application and irrigation water quality,put forward safeguard measures for organic agriculture in terms of soil,fertilizer and water,and finally came up with recommendations for strengthening the use of soil fertilizers in organic agriculture.展开更多
Utilization of nitrogen (N) element is a common practice used to reach profitable yields in horticultural crops and N supply can be used as a tool to manipulate the enhancement of phytochemicals and minerals in vege...Utilization of nitrogen (N) element is a common practice used to reach profitable yields in horticultural crops and N supply can be used as a tool to manipulate the enhancement of phytochemicals and minerals in vegetable crops to address consumer-oriented quality production. Hence the study was aimed to investigate the effect of N application on leaf morphology, ascorbic acid content, phenolic acids, flavonoids, mineral content, and nitrate residues in three lettuce varieties (two green leafy lettuce, Multigreen 1 and Multigreen 3; one red leafy lettuce, Multired 4) grown in a closed hydroponic system (grave^-film) at harvest. Nitrogen was applied as ammonium nitrate (NH4NO3) at six different concentrations of 0, 60, 90, 120, 150 and 180 mg L^-1. The results obtained during 2015 and 2016 seasons were similar and demonstrated variety dependent responses with respect to different N application rates. Multigreen 3 was more sensitive to N supply and showed higher amount of nitrate residue at harvest. Variety Multired 4 was less sensitive to N supply followed by Multigreen 11 Although N supply at 120 mg L^-1 improved the yield and the number of leaves in Multigreen 3, overall 90 mg L^-1 can be recommended for these lettuce varieties to improve the yield and the accumulation of ascorbic acid content, phenolic acids mainly caffeic, caftaric acids, quercetin (the important flavonoid in lettuce), and Fe and Mn contents. Furthermore, the concentration of 90 mg L^-1 improved the antioxidant property (FRAP and ABTS^+) and reduced the nitrate accumulation, ensuring safe food for consumers.展开更多
Utilizing straw as feed and applying cattle and sheep manure fertilizer to the field plays an important role in solving the shortage of feed raw material resources,alleviating the conflict between human beings and liv...Utilizing straw as feed and applying cattle and sheep manure fertilizer to the field plays an important role in solving the shortage of feed raw material resources,alleviating the conflict between human beings and livestock,and realizing the full utilization of straw as a resource and green and low-carbon circular development.We carried out an investigation on the feed utilization of crop straw in Sichuan Province,comprehensively grasped the crop straw resources and its utilization as feed in this province,deeply analyzed the existing problems,and put forward countermeasures and suggestions according to the actual situation in Sichuan,which plays an important role in accelerating the process of straw feed utilization,promoting green development,implementing the rural revitalization strategy,and building a beautiful Sichuan.展开更多
The primary challenge of mineland revegetation is the establishment of species able to cope with low availability of nutrients,especially in steep slopes such as of mine pits.We evaluated plant growth response and nut...The primary challenge of mineland revegetation is the establishment of species able to cope with low availability of nutrients,especially in steep slopes such as of mine pits.We evaluated plant growth response and nutrient use efficiency(NUE)of two promising native Fabaceae species(Dioclea apurensis—liana from metalliferous savannas;Bauhinia longipedicellata—tree from Amazon rainforest)from the Caraja´s Mineral Province,eastern Amazon-Brazil.Plants were grown separately in 2-kg pots filled with mining waste.Substrates were fertilized with nitrogen,phosphorus,potassium(NPK),lime,and micronutrients.The results showed increments on growth of both species when nutrients were applied to the mining waste.D.apurensis showed increases in leaf area,plant height,stem diameter,and shoot dry mass production when NPK or NPK?micronutrients were applied,while B.longipedicelata was responsive to application of NPK?lime or NPK?lime?micronutrients.Further,D.apurensis showed higher NUE than B.longipedicelata,especially at the lowest doses of N,P and K.These findings may indicate a substantial advantage of D.apurensis for mineland revegetation,as this species may require lower nutrient inputs,being,therefore,a more sustainable way to revegetate degraded areas.展开更多
There is a rapid development of lawn industry, however, the researches on lawn culture, maintenance and its mechanisms lag behind. Studies of drought-resistance, fertilization, management and maintenance of lawn are d...There is a rapid development of lawn industry, however, the researches on lawn culture, maintenance and its mechanisms lag behind. Studies of drought-resistance, fertilization, management and maintenance of lawn are discussed in this paper. Besides, problems with the research on lawn culture and its maintenance in China are also analyzed. For example, soil has been destroyed seriously by the production of wrapping sward, but the studies on turf medium are deficient. Besides, the maintenance and management of lawn have not a standard due to the shortage of studies on turf quality assessment; applications of high-technique to lawn sciences are inadequate too. The developing tendency of lawn research in China is suggested at the end of this paper to help for the further studies in this field.展开更多
Nitrogen fertilizer application is an important means to promote cotton production in saline-alkali land.A metaanalysis and regression analysis of 49 peer-reviewed studies were conducted using yield data(373 data poin...Nitrogen fertilizer application is an important means to promote cotton production in saline-alkali land.A metaanalysis and regression analysis of 49 peer-reviewed studies were conducted using yield data(373 data points),dry matter accumulation(114 data points),and water use efficiency(157 data points)to quantify the effect of nitrogen fertilizer on the yield,dry matter accumulation,and water use efficiency of cotton in saline-alkali land in China for different planting management practices and different growing environments.The results showed that the nitrogen application significantly improved the yield,dry matter accumulation,and water use efficiency by 34.11%,36.27%,and 33.87%,respectively,compared with no nitrogen application.The largest improvements in the yield,dry matter accumulation,and water use efficiency occurred in areas where saline-alkali land had been improved for many years,in Eastern China,South Central China,and Northwest China(areas with annual average precipitation≤200 mm or>800 mm,and annual average evaporation≤800 mm or>2400 mm),in areas with trickle irrigation,and fields with a planting density of 100000 to 250000 plants/hm2.Cotton exhibited the optimal response to nitrogen application at a rate of 300-375 kg/hm2,a basal application ratio of 20%-40%,and top-dressing in the cotton bud,flowering boll,and full boll stages.The effect of nitrogen application increased as the salinity increased.A suitable nitrogen application rate,top-dressing ratio,and top-dressing period are crucial for increasing cotton production in saline-alkali land,although environmental differences and planting measures have to be considered.This study provided information on the correct application of nitrogen fertilizer to maximize its benefits and suggests controlling nitrogen fertilizer inputs in agriculture to protect the soil environment and ensure sustainable agricultural development.展开更多
Since there are some problems in the previous cam of deep-fertilization liquid fertilizer applicator,such as poor precision and low-fertilization performance,a method of the contour line of a cam was proposed based on...Since there are some problems in the previous cam of deep-fertilization liquid fertilizer applicator,such as poor precision and low-fertilization performance,a method of the contour line of a cam was proposed based on Matlab GUI development platform.Bernoulli’equation between the liquid fertilizer and the pressure valve of the fertilizer-spraying needle was founded.Moreover,the motion angles of a rise travel and return travel were corrected and the corresponding parameters of the contour line of the cam were obtained.Equations of cam moving from rise travel to return travel were derived according to the simple harmonic motion.In addition,3D model of cam was established by applying the Pro/E software and the rationality of the cam design was verified.The static analysis of the cam was carried out under working conditions and the corresponding dynamics analysis was performed based on D’Alembert’s principle.And then relationships between the binding force and the drag torque were obtained.A bench test indicates that when the pressure of a hydraulic pump is 0.5 MPa and the velocity of a output shaft is 50 r/min,the average consumption of the fertilizer is 19.7 mL for each measurement,which meets the corresponding agronomic requirement,i.e.20 mL.When the rotation angle of the cam is 8.6°and the rise displacement of a plunger is 0.84 mm,the mouth of the fertilizer-spraying needle sprayed liquid fertilizer as soon as it got into the soil and stopped spraying as soon as it got out of the soil.The results show that the designed contour line of the cam meets the requirement,that is,the mouth of the fertilizer-spraying needle should spray liquid fertilizer as soon as it gets into the soil and stop spraying as soon as it gets out of the soil,which meets the agronomic requirements,that is,fertilizer should be sprayed deeply and precisely.And this study lays a theoretical foundation for designing the cam of intermittent type distributor and provides relevant parameters.展开更多
基金Supported by Special Fund of Agro-scientific Research in Public Interest(201303129)Analysis of Sulforaphane Content in Brassica juncea Coss.var.foliosa Bailey and Related SSR Markers(2017FD200)National Staple Vegetable Industrial Technology System(CARS-23-G37)
文摘This study was conducted to provide reference for rational fertilization and agrochemical application in cucumber plantation,and relieve the problem of environmental pollution and vegetable agrochemical residues. The effects of different combinations of fertilization and agrochemical application on cucumber yield and cost input were investigated. Four treatments were conducted,including T1( conventional fertilization + conventional agrochemical application,CK),T2( conventional fertilization + recommended agrochemical application),T3( recommended fertilization + conventional agrochemical application) and T4( recommended fertilization + recommended agrochemical application). The results showed that T4 had fewer kinds of fertilizers and agrochemicals than that of T1,and had a yield increasing effect on cucumber,and the yield increase was 7 003. 5 kg/hm^2,with an increasing rate of 19. 25%; and it also had obvious cost-saving and benefit-increasing effects,specifically,the cost was saved by 10 941 yuan/hm^2 and the benefit was increased by 31 951. 5 yuan/hm^2. The results of this experiment were satisfactory,and higher benefit was obtained with lower input. This study will provide reference for cucumber planter to choose fertilizers and agrochemicals,and lays a foundation for alleviating the ecological soil problems.
基金supported by the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2011BAD16B14,2012BAD20B05)the Agricultural Science and Technology Independent Innovation Funds of Jiangsu Province,China(CX(11)2011)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China(PAPD)
文摘The objective of this study was to determine the morphology mechanism of nitrogen (N) fertilizer rates and ratio on lodging resistance through analying its effects among lodging index (LI), lodging-related morphological traits and physical strength in basal intemodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels (0, 150 and 300 kg ha-L) and two ratios of basal to topdressing (8:2 and 5:5) with two super rice cultivars (Yliangyou 2 and Wuyunjing 23), were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal intemodes and culm's physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was significant greater than that of Wuyunjing 23 due to larger bending moment by whole plant (WP) with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no significant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength (M) in basal intemodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress (BS) of Wuyunjing 23 and section modulus (Z) of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction ofBS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, influencing their M indirectly. These results suggested that breaking strength was the key factor influencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of japonica super rice influenced breaking strength, as well as lodging index, respectively.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30070454).
文摘A pot experiment was conducted to study the effects of different nitrogen application time (during the tillering or the booting stages) with the same nitrogen rates on the caryopsis development and grain quality of rice variety Yangdao 6. The increased nitrogen fertilizer (urea), especially applied during the booting stage, could evidently increase the milled rice rate, head rice rate and protein content in rice grains compared with the control (no nitrogen application), and decrease chalky grain rate and amylose content. Moreover, the increased nitrogen fertilizer significantly affected the caryopsis development and enhanced the grain weight when nitrogen applied during the tillering and the booting stages, especially during the booting stage. During caryopsis development the increased nitrogen fertilizer applied during the tillering and booting stages could obviously decrease the total starch and amylose contents, but not obviously for the amylopectin content in rice grain. Increased topdressing of nitrogen fertilizer, especially applied during the booting stage, had significant effect on the development and structures of amyloplasts and proteinoplasts. That is, it could change the distribution, number and shape of amyloplasts and proteinoplasts in the endosperm cells especially in grain abdomen, Compared with the control the arrangements of amyloplasts and proteinoplasts were closer, with more numbers, higher density and less interspaces each ohter. Furthermore, most amyloplasts showed polyhedron under the increased nitrogen fertilizer level.
基金supported by 2008 Program for New Century Excellent Talents in University of Chinathe National Natural Science Foundation of China(70873108)+1 种基金Zhejiang Provincial Natural Science Foundation, China (Z607126)the Ministry of Education of China (2007JJD630014)
文摘Agricultural chemical use has caused a public concern over environmental issue while decisions about applying chemicals are made by individual farmers. The critical decision-making role of farmers relative to agricultural chemical use creates a need for accurate information on their perceptions of various chemical-related hazards and the factors that may influence such judgments. Based on data collected from 177 land operators at Xinxiang County in Henan Province of China, an empirical analysis is conducted to examine the relationship between farmers' character and the behavior of fertilizer application. Study findings reveal that: the characteristics of household head and household, and the nature of farming management positively affect the amount of fertilizers applied; information on fertilizers and the knowledge about environmental impact of fertilizer application have negative impacts by contrast. To formulate effective pollution control policies at the farm level, it is imperative for policy-makers to convey information to producers by demonstration projects, technical assistance, and education programs. Under a changed political environment, some combination of education and economic incentives could be lower cost and more effective tools for achieving desired environmental conservative goals.
文摘Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied. The experiments on long-term application of K fertilizer and wheat straw to soil in Hebei fluvo aquic soil and Shanxi brown soil in northern China were begun in 1992. The results showed that K fertilizer and straw could improve the yields of wheat and maize with the order of NPK + St 〉 NPK 〉 NP + St 〉 NP, and treatment of K fertilizer made a significant difference to NP, and the efficiency of K fertilizer in maize was higher than in wheat under rotation system of Hebei. In contrast with Shanxi, the wastage of soil potassium was a more serious issue in the rotation system in Hebei, only treatment of NPK + St showed a surplus of potassium and the others showed a wane. K fertilizer and straw could improve the content of water-soluble K, nonspecifically adsorbed K, non-exchangeable K, mineral K, and total K in contrast to NP; however, K fertilizer and straw reduce the proportion of mineral K and improve proportion of other forms of potassium in the two locating sites. Compared with the beginning of orientation, temporal variability character of soil K content and proportion showed a difference between the two soil types; furthermore, there was a decrease in the content of mineral K and total K simultaneously in the two locating sites. As a whole, the effect of K fertilizer applied to soil directly excelled to wheat straw to soil. Wheat straw to soil was an effective measure to complement potassium to increase crop yield and retard the decrease of soil K.
基金supported by the National Key Research and Development Project(2017YFD0801302)。
文摘The hyperaccumulator Sedum alfredii Hance(S.alfredii)may be employed for zinc(Zn)and cadmium(Cd)-polluted soil remediation.However,the low phytoremediation efficiency,related to the low biomass production,limits its use with that purpose.In this experiment,nitrogen(N),phosphorus(P),and potassium(K)fertilizers,and organic manure were applied to investigate the phytoremediation ability of S.alfredii.Hydroponic and pot experiments were conducted using Zn-Cd polluted soil.The hydroponic experiment indicated that appropriate fertilizer application could increase(p<0.05)the amount of accumulated Zn and Cd in S.alfredii.When N supply ranged from 0.5 to 2.5 mmol L^(−1),it could improve growth and accumulation of Zn and Cd in whole plants of S.alfredii.The 1 mmol L^(−1) N was an optimal N dosage for shoot biomass production and Cd accumulation in shoots,while the 2.5 mmol L^(−1) was an optimal N dosage for Zn accumulation in shoots.Both low(<0.05 mmol L^(−1))and high(>0.8 mmol L^(−1))P supply decreased growth,and Zn/Cd accumulation in whole plants of the studied species.The 0.1 mmol L^(−1) P was an optimal dosage for S.alfredii biomass production and Zn/Cd accumulation in shoots.The supply levels within the range from 0.3 to 1 mmol L^(−1) K could significantly improve the biomass production of S.alfredii and its capability to accumulate Zn and Cd in the biomass.The 0.5 mmol L^(−1) K was an optimal dosage for the whole biomass production and Zn accumulation in shoots,while the 1 mmol L^(−1) was an optimal K dosage for Zn accumulation in shoots,which was 17.2%higher than the control.Moreover,the soil pot experiment showed that the combination of organic(fermented manure)and inorganic fertilizers made significant effects on the Zn and Cd-polluted soil remediation by S.alfredii.These effects varied,however,with the application of different proportions of N,P,K and organic matter.The Zn accumulation by S.alfredii reached the highest efficiency ability under the highest fertilizer mixing rate(N:50 mg kg^(−1),P:40 mg kg^(−1),K:100 mg kg^(−1),organic matter:1%).Even more,S.alfredii showed the strongest ability to accumulate Cd with a lower fertilizer mixing rate(N:25mg kg^(−1),P:20mg kg^(−1),K:50 mg kg^(−1),organic matter:0.5%).
基金Supported by Black Soil Conservation Tillage and Oriented Cultivation Technology Research (GB06B107-1)Innovation Fund of Northeast Agricultural University (CXP7003-3-3)+1 种基金Northeast Agricultural University and the Scientific Research Fund of Heilongjiang Province to Black CollegesUniversities Cold Key Laboratory of Utilization and Protection of Open-funded Projects (GXS08-5)
文摘By two years (2007-2008) located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, Heilongjiang Province. The results showed that the combined application of organic and inorganic fertilizers could increase the organinc matter, alkaline nitrogen, available phosphorus and available potassium. At the same time, the increasing application of organic fertilizer could reduce the soil bulk density and improve the field moisture capacity. Field moisture capacity and organic matter of the combined application of high quantities of organic manure and inorganic fertilizers AtB5 treatment increased the fhstest, organic matter increased by 3.33 g. kg and field moisture capacity increased by 11.25% than the beginning of the experiment. Under the same fertilization, the combined application of organic and inorganic fertilizers' increasing production range was higher than the single chemical fertilizers' which was from 0.8% to 9.4%. The results showed that the combined application of organic and inorganic fertilizers could increase the nutrient contents of soil and also was the highest productivity contribution to black soil fertility. It was the best fertilization structure of increasing productivity level and improving the soil fertility.
基金supported by the National Basic ResearchProgram of China (2007CB109300)
文摘The effect of fertilizer application on biomass dry weight and element distribution of various organs of maize was investigated from the aspect of microscopic view to disclose the internal mechanism of fertilizer effect on crop. Five fertilizer treatments: no fertilizer (CK), nitrogen phosphorus fertilizer (NP), nitrogen potassium fertilizer (NK), phosphorus potassium (PK), and nitrogen phosphorus potassium fertilizer (NPK) were designed. Field experiment on the response of biomass dry weight and N, P, K, Cu, Zn, Fe, and Mn element distribution of stem, leaf and seed of maize (Zea mays L.) to different fertilizer treatments application was carried out. The results showed that dry weight and element content of various organs of maize were different. N content of various organs followed this order leaf〉 seed 〉 stem; P content of various organs was seed 〉 leaf〉 stem; K content was stem 〉 leaf〉 seed; and Fe content was leaf〉 stem 〉 seed. Fertilizer application reduced the differences of N, P, K, and Fe contents of various organs, and changed the size order of the dry weight and the Cu and Zn contents of leaf, seed and stem. Except for individual treatment, the response direction of N, P and Fe elements to fertilizer application was similar to Cu and Zn. The response of element content of various organs of maize to different fertilizer combinations was also different. The response extent of N, P and K major elements to fertilizer application was larger than microelement of Cu, Zn, Fe, and Mn; the response extent of stem and leaf was larger than seed; the response to NPK fertilizer treatment was bigger than NP, NK and PK. In the whole, response differences of element distribution to various fertilizer treatments were not remarkable. Besides, element distribution of various organs of maize was also influenced by the mutual effect of fertilizer varieties. The response direction and extent of various element distributions to different fertilizer treatments had both similarities and differences. Adjusting fertilizer application could change the biomass dry weight and element distribution of various organs of maize, thus promote the uptake and cycle of nutrient. This investigation could provide useful information for high production.
基金Supported by Special Project for Construction of Modern Agricultural Industrial Technology System(CARS-12)Key Special Scientific and Technological Research Project of Henan Province(151100111200)+1 种基金Key Scientific and Technological Planning Project of Henan Province(162102110011)Planning Project for National Key Research and Development(2016YFD0101300)
文摘To find proper nitrogen fertilizer application mode of rapeseed( Brassica napus L.),promote the high and stable yield of rapeseed,field experiment was carried out to study the effect of nitrogen fertilizer application modes on the yield and economic traits of Fengyou 10 rapeseed planted in two different fertility soils,and characteristics and differences of responses of different fertility soils to nitrogen fertilizer application modes were compared and analyzed. The results showed that the yield and related economic traits of rapeseed treated by nitrogen fertilizer were higher than the control group; in the nitrogen fertilizer treatment group,when the nitrogen fertilizer was applied as the base fertilizer and wintering fertilizer at the ratio of 7∶ 3,the rapeseed yield was higher than the control group and reached the highest; when the nitrogen fertilizer was applied as the base fertilizer,wintering fertilizer,and bud fertilizer at the ratio of 5∶ 3∶ 2,the rapeseed yield was significantly higher than the control group but was the lowest. These indicate that sufficient nitrogen supply is the basis for normal growth and development of rape seedlings. When the pure nitrogen fertilizer was at 192 kg/ha and the ratio of base fertilizer and wintering fertilizer was 7∶ 3,it can better coordinate the high yield of rapeseed and overall use of nitrogen fertilizer,and obtain higher rapeseed yield.
文摘Most research-based fertilizer inputs proposed for small scale farmers to increase their productivity do not achieve the required results and should consider indigenous practices. This study evaluates the practices of nutrient fertilizer input by farmers and researchers and relates them to their corresponding yields and profit so as to establish the appropriateness of the practices in 13 districts of the Northern regions of Ghana. Soil nutrients assessment of Nitrogen (N), Phosphorus (P) and Potassium (K) contents used to evaluate the soil NPK status was based on previous studies. Data on fertilizer application by farmers and researchers were obtained from the Savanna Agricultural Research Institute (SARI). The amount of N, P and K fertilizer input in 13 Districts and its associated maize grain yields by both farmers (89) and researchers were calculated and compared using two-sample t-test. The t-test results indicated that average amount of fertilizer input by researchers was significantly (p < 0.05) higher than the average amount of fertilizer input by the smallholder farmers, but the high fertilizer input did not significantly (p = 0.74) increase researchers’ maize yields and profits in all 13 study districts grouped together, but there was maize increment in only eight districts. On the average, farmers from five districts applied low fertilizer and recorded low yields. However, when researchers increased quantities of fertilizer applied in these five districts, yield significantly (p < 0.05) increased. The outcome showed that smallholder farmers in these five districts could increase maize yields by 36% in the region should they adopt the maize production strategy by the researchers. The study concluded that, for best options, recommended fertilizer doses to enhance maize yields should consider district-specific farmers’ practices and soil NPK status. The study could enable better implementation of location-based nutrient recommendation in the Northern Region of Ghana.
基金Supported by the Second Batch of Modern Agricultural Industry Technology System Project in Hubei Province
文摘This paper studied the effect of reducing application of chemical fertilizer,increasing application of functional organic fertilizer and trace elements and fully using biological pesticides on physiological traits,yield and quality of radish. The results showed that applying functional organic fertilizer and trace elements and fully using biological pesticides could help to significantly improve the radish fleshy root yield,increase soluble sugar and vitamin C content,reduce crude fiber and nitrate content,but had no significant influence on radish moisture content,glucosinolates and chlorpyrifos content in organophosphorus pesticides.
文摘In order to provide a theoretical basis for apple cultivation techniques and to provide a reference for preparation of scientific management measures,the occurrence and damage status of apple little leaf in northern Guizhou was investigated,and fertilizer control test against the disease was also conducted.(1)Apple little leaf occurred from April to October in apple producing areas in northern Guizhou every year,with heavy incidence from April to May,light incidence from June to July,and the lightest incidence from August to October.(2) Effectiveness test showed that application of zinc sulfate fertilizer 135 g + cow dung 10 kg received the best control effect,followed by zinc sulfate fertilizer 165 g + cow dung 10 kg,then zinc sulfate fertilizer 105 g + cow dung 10 kg and zinc sulfate fertilizer 150 g + cow dung 10 kg.(3) Based on local environmental conditions,occurrence and damage situation,incidence conditions and fertilizer efficacy test,comprehensive prevention and control technology with rational supplement of zinc fertilizer could be used to control apple little leaf.
文摘The response of rice to N fertilizer applicationhas shown that high rates of N application donot always ensure a proportional increase inyield due to high N losses. A model, ORYZA-0 was developed by ten Berge for designingoptimum N fertilizer management strategy inrice. We evaluated the performance ofORYZA-0 in Jinhua, Zhejiang Province. ORYZA-0 includes N uptakes, partition-ing of N among the organs, and utilization ofleaf N in converting solar energy to dry mat-ter. It can predict the amount and time of Nfertilizer application to achieve a maximumbiomass or yield combining with Price algo-rithm optimization procedure.
文摘This paper summarized the requirements of organic agriculture for soil environment,fertilizer application and irrigation water quality,put forward safeguard measures for organic agriculture in terms of soil,fertilizer and water,and finally came up with recommendations for strengthening the use of soil fertilizers in organic agriculture.
基金funding from the National Research Foundation Grant, South Africa (98352) for Phytochemical Food Network to Improve Nutritional Quality for Consumers
文摘Utilization of nitrogen (N) element is a common practice used to reach profitable yields in horticultural crops and N supply can be used as a tool to manipulate the enhancement of phytochemicals and minerals in vegetable crops to address consumer-oriented quality production. Hence the study was aimed to investigate the effect of N application on leaf morphology, ascorbic acid content, phenolic acids, flavonoids, mineral content, and nitrate residues in three lettuce varieties (two green leafy lettuce, Multigreen 1 and Multigreen 3; one red leafy lettuce, Multired 4) grown in a closed hydroponic system (grave^-film) at harvest. Nitrogen was applied as ammonium nitrate (NH4NO3) at six different concentrations of 0, 60, 90, 120, 150 and 180 mg L^-1. The results obtained during 2015 and 2016 seasons were similar and demonstrated variety dependent responses with respect to different N application rates. Multigreen 3 was more sensitive to N supply and showed higher amount of nitrate residue at harvest. Variety Multired 4 was less sensitive to N supply followed by Multigreen 11 Although N supply at 120 mg L^-1 improved the yield and the number of leaves in Multigreen 3, overall 90 mg L^-1 can be recommended for these lettuce varieties to improve the yield and the accumulation of ascorbic acid content, phenolic acids mainly caffeic, caftaric acids, quercetin (the important flavonoid in lettuce), and Fe and Mn contents. Furthermore, the concentration of 90 mg L^-1 improved the antioxidant property (FRAP and ABTS^+) and reduced the nitrate accumulation, ensuring safe food for consumers.
基金Mutton Sheep High-Quality and High-Yield Forage Variety Selection and Production Application Post of Sichuan Mutton Sheep Innovation Team(sccxtd-2020-14).
文摘Utilizing straw as feed and applying cattle and sheep manure fertilizer to the field plays an important role in solving the shortage of feed raw material resources,alleviating the conflict between human beings and livestock,and realizing the full utilization of straw as a resource and green and low-carbon circular development.We carried out an investigation on the feed utilization of crop straw in Sichuan Province,comprehensively grasped the crop straw resources and its utilization as feed in this province,deeply analyzed the existing problems,and put forward countermeasures and suggestions according to the actual situation in Sichuan,which plays an important role in accelerating the process of straw feed utilization,promoting green development,implementing the rural revitalization strategy,and building a beautiful Sichuan.
文摘The primary challenge of mineland revegetation is the establishment of species able to cope with low availability of nutrients,especially in steep slopes such as of mine pits.We evaluated plant growth response and nutrient use efficiency(NUE)of two promising native Fabaceae species(Dioclea apurensis—liana from metalliferous savannas;Bauhinia longipedicellata—tree from Amazon rainforest)from the Caraja´s Mineral Province,eastern Amazon-Brazil.Plants were grown separately in 2-kg pots filled with mining waste.Substrates were fertilized with nitrogen,phosphorus,potassium(NPK),lime,and micronutrients.The results showed increments on growth of both species when nutrients were applied to the mining waste.D.apurensis showed increases in leaf area,plant height,stem diameter,and shoot dry mass production when NPK or NPK?micronutrients were applied,while B.longipedicelata was responsive to application of NPK?lime or NPK?lime?micronutrients.Further,D.apurensis showed higher NUE than B.longipedicelata,especially at the lowest doses of N,P and K.These findings may indicate a substantial advantage of D.apurensis for mineland revegetation,as this species may require lower nutrient inputs,being,therefore,a more sustainable way to revegetate degraded areas.
文摘There is a rapid development of lawn industry, however, the researches on lawn culture, maintenance and its mechanisms lag behind. Studies of drought-resistance, fertilization, management and maintenance of lawn are discussed in this paper. Besides, problems with the research on lawn culture and its maintenance in China are also analyzed. For example, soil has been destroyed seriously by the production of wrapping sward, but the studies on turf medium are deficient. Besides, the maintenance and management of lawn have not a standard due to the shortage of studies on turf quality assessment; applications of high-technique to lawn sciences are inadequate too. The developing tendency of lawn research in China is suggested at the end of this paper to help for the further studies in this field.
基金supported by a start-up from the National Natural Science Foundation of China(Grant No.52069026)Xinjiang Production and Construction Corps“strong base”science and technology leading talent project(Grant No.2022CB013-02)the Xinjiang Production and Construction Crops International Science and Technology Cooperation Project(Grant No.2021BC003).
文摘Nitrogen fertilizer application is an important means to promote cotton production in saline-alkali land.A metaanalysis and regression analysis of 49 peer-reviewed studies were conducted using yield data(373 data points),dry matter accumulation(114 data points),and water use efficiency(157 data points)to quantify the effect of nitrogen fertilizer on the yield,dry matter accumulation,and water use efficiency of cotton in saline-alkali land in China for different planting management practices and different growing environments.The results showed that the nitrogen application significantly improved the yield,dry matter accumulation,and water use efficiency by 34.11%,36.27%,and 33.87%,respectively,compared with no nitrogen application.The largest improvements in the yield,dry matter accumulation,and water use efficiency occurred in areas where saline-alkali land had been improved for many years,in Eastern China,South Central China,and Northwest China(areas with annual average precipitation≤200 mm or>800 mm,and annual average evaporation≤800 mm or>2400 mm),in areas with trickle irrigation,and fields with a planting density of 100000 to 250000 plants/hm2.Cotton exhibited the optimal response to nitrogen application at a rate of 300-375 kg/hm2,a basal application ratio of 20%-40%,and top-dressing in the cotton bud,flowering boll,and full boll stages.The effect of nitrogen application increased as the salinity increased.A suitable nitrogen application rate,top-dressing ratio,and top-dressing period are crucial for increasing cotton production in saline-alkali land,although environmental differences and planting measures have to be considered.This study provided information on the correct application of nitrogen fertilizer to maximize its benefits and suggests controlling nitrogen fertilizer inputs in agriculture to protect the soil environment and ensure sustainable agricultural development.
基金This research was supported by the National Natural Science Foundation of China(Grant No.51675093)“Young Talents”Project of Northeast Agricultural University(Grant No.18QC19).
文摘Since there are some problems in the previous cam of deep-fertilization liquid fertilizer applicator,such as poor precision and low-fertilization performance,a method of the contour line of a cam was proposed based on Matlab GUI development platform.Bernoulli’equation between the liquid fertilizer and the pressure valve of the fertilizer-spraying needle was founded.Moreover,the motion angles of a rise travel and return travel were corrected and the corresponding parameters of the contour line of the cam were obtained.Equations of cam moving from rise travel to return travel were derived according to the simple harmonic motion.In addition,3D model of cam was established by applying the Pro/E software and the rationality of the cam design was verified.The static analysis of the cam was carried out under working conditions and the corresponding dynamics analysis was performed based on D’Alembert’s principle.And then relationships between the binding force and the drag torque were obtained.A bench test indicates that when the pressure of a hydraulic pump is 0.5 MPa and the velocity of a output shaft is 50 r/min,the average consumption of the fertilizer is 19.7 mL for each measurement,which meets the corresponding agronomic requirement,i.e.20 mL.When the rotation angle of the cam is 8.6°and the rise displacement of a plunger is 0.84 mm,the mouth of the fertilizer-spraying needle sprayed liquid fertilizer as soon as it got into the soil and stopped spraying as soon as it got out of the soil.The results show that the designed contour line of the cam meets the requirement,that is,the mouth of the fertilizer-spraying needle should spray liquid fertilizer as soon as it gets into the soil and stop spraying as soon as it gets out of the soil,which meets the agronomic requirements,that is,fertilizer should be sprayed deeply and precisely.And this study lays a theoretical foundation for designing the cam of intermittent type distributor and provides relevant parameters.