Field plot experiment was conducted to study the effects of two slow-re- lease fertilizers and balanced fertilization on dry matter accumulation, yield, fertilizer use efficiency, nitrogen, phosphorus and potassium up...Field plot experiment was conducted to study the effects of two slow-re- lease fertilizers and balanced fertilization on dry matter accumulation, yield, fertilizer use efficiency, nitrogen, phosphorus and potassium uptake of peppers at Jiangna Town, Yanshan County, Yunnan Province in 2011. The results showed that the dry matter accumulation in dried pepper plant, pepper yield, nitrogen, phosphorus, potassium uptake in peppers were significantly increased in all the fertilizer treat- ments, compared with those in control (no fertilizer). Compared with conventional fertilization, balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer significantly increased dried pepper economic output by 20.94%, 17.5% and 14.54%, nitrogen uptake in dried peppers by 21.53%,18.46% and 13.19%, phosphorus uptake in dried peppers by 14.08%, 15.76% and 10.44%, potassium uptake in dried peppers by 22.66%, 15.73% and 16.28%; they also in- creased nitrogen and potassium use efficiency, but reduced potassium use efficiency due to the increased potassium addition. In treatments with balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer, the nitrogen utiliza- tion was 5.84%, 7.14% and 8.33% higher and the phosphorus utilization was 3.32%, 3.27% and 2.47% higher than those in treatment with conventional fertiliza- tion. In addition, the nitrogen application could be reduced by 20%-50% by bal- anced fertilization and the two slow-release fertilizers, thereby reducing environmen- tal pollution. Slow-release fertilizers could also reduce the frequency of fertilization and labor costs.展开更多
A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP...A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK>MNP>MN>NPK>NP>M>N>the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N>P>K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.展开更多
A pot experiment was conducted to determine the dynamics of soil microbial biomass in a rainfed soil under wheat cultivation at the University of Arid Agriculture, Rawalpindi, Pakistan. The treatments applied were: 1)...A pot experiment was conducted to determine the dynamics of soil microbial biomass in a rainfed soil under wheat cultivation at the University of Arid Agriculture, Rawalpindi, Pakistan. The treatments applied were: 1) a control (CK), 2) NPK (0.44-0.26-0.18 g pot-1), 3) farmyard manure (FYM, 110 g pot-1), 4)poultry manure (PM, 110 g pot-1), 5) FYM (110 g pot-1) + NPK (0.44-0.26-0.18 g pot-1), 6) poultry manure (PM, 110 g pot-1) + NPK (0.44-0.26-0.18 g pot-1), 7) FYM (110 g pot-1) + NPK(S) (0.44-0.26-0.18 g pot-1, one half of the NPK at sowing and the other half one month after sowing), and 8) PM (110 g pot-1) + NPK(S) (0.44-0.26-0.18 g pot-1, one half of the NPK applied at sowing and the other half one month after sowing). The experiment was laid out using a completely randomized design with three replications. Microbial biomass C, N and P contents increased continuously from the beginning of the experiment up to the three-leaf stage. A slight decline was observed at the tillering stage in all treatments except with the organic manures + NPK(S) treatments. After tillering there was an increase in all treatments to the recorded maximum point at the full heading stage in all treatments except with the organic manures + NPK(S) treatments. In the FYM + NPK(S) and PM + NPK(S) treatments; however, there was a continuous increase in microbial biomass up to the heading stage. At the harvesting stage a sharp decline was noted in all treatments. The C:N ratio of microbial biomass in tested soil ranged from 7.8 to 11.3, while C:P ratio of microbial biomass in the tested soil ranged from 22.6 to 35.1 throughout all growth stages of the wheat crop.展开更多
Twenty eight species of forage crops were planted on acid soils derived from Quaternary red clay (pH 4.16)and red sandstone (pH 4.55) to study genotypic differences of the forage crops in tolerance to acid soils as af...Twenty eight species of forage crops were planted on acid soils derived from Quaternary red clay (pH 4.16)and red sandstone (pH 4.55) to study genotypic differences of the forage crops in tolerance to acid soils as affected by liming, phosporus and potassium fertilizer application. Eight forage species, Lolium multiflorum L., Brachiaria decumbens, Digitaria sumtisii, Melinis minutiflora, Paspalum dilatatum, Paspalum wettsteinii,Sataria viridis Beanv and Shcep’s Festuca, were highly tolerant to acid soils, and grew relatively well in the tested soils without lime application, whereas most of the other 20 tested forage species such as Lolium perenne L., Meadow Festuca and Trifolium pratense L. were intolerant to acid soils, showing retarded growth when the soil pH was below 5.5 and significant increase in dry matter yields by phosphrus fertilizer application at soil pH 6.0. Results showed that large differences in tolerance to acid soils existed among the forage species,and tolerance of the forage species to acid soils might be closely associated with their tolerance to Al and P efficiency.展开更多
Over a period of two years , field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv. Lu-Bai 3), autumn greens (B. chinensis...Over a period of two years , field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv. Lu-Bai 3), autumn greens (B. chinensis L., cv. Piao-Geng-Bai), winter greens (B. var. rosularis Tsen et Lee, cv. You-Dong-Er), and summer greens (B. chinensis L., cv. Zao-Shu 5), respectively. Each experiment included one CK treatment without K, N and P fertilizers applied, and four treatments with from low to high doses, 0-300 kg hm-2 for Chinese cabbage, 0-150 kg hm-2 for autumn and winter greens and 0-180 kg hm-2 for summer greens, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One treatment of K fertilizer in the form of muriate of potash (MOP) applied at high levels (150 or 180 kg hm-2) together with N and P fertilizers was included in the experiments of autumn, winter and summer greens , respectively, in order to compare the effects of SOP and MOP. The market yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. K fertilization increased not only K contents but also the amounts of N, P and K absorbed in shoots of autumn, winter and summer greens, which were statistically significantly correlated to their yields. It can also be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased. As compared to MOP, SOP was more effective on the yields and quality of autumn, winter and summer greens at the high levels of fertilization.展开更多
Generally, the diameter of organic melon fruit relatively short (the fruit is small), weight of fruit just as big as 1.25-1.49 kg only, while weight of inorganic melon fruit can reach 2-3 kg. The research was conduc...Generally, the diameter of organic melon fruit relatively short (the fruit is small), weight of fruit just as big as 1.25-1.49 kg only, while weight of inorganic melon fruit can reach 2-3 kg. The research was conducted by experiment method with the aim to enhance quality of the organic melon fruit. Experiment I is: N, P and K fertilizer solution concentration as main plot (0, 20, 30, and 40 g L^-1) and dose of cow manure fertilizer as sub plot (0, 10, 15, and 20 ton hal) (there are 16 treatment combinations). Experiment II is kinds of dung as main plot (chicken, cow, and goat) and dose of fertilizer as sub plot (20, 25, and 30 ton hat) (there are 9 treatment combinations). Experiment III is dose of cow manure fertilizer as main plot (15, 20, 25, and 30 ton hal) and gibberellins concentration as sub plot (0, 30, 60, and 120 ppm) and (there are 16 treatment combinations). Each of the treatment combination replicated 3 times. The result showed that chicken, cow, and goats manure can be used in organic cultivation of melons, and cow manure has the highest potential. The role of the dose is relatively low in plant growth, but to improve the quality of fruit need dose of 10-15 tons hat. The addition of inorganic NPK fertilizer solution or use of gibberellins can increase growth and fruit quality of melon (the used of gibberellins are recommended).展开更多
Inorganic fertilizer NPK (nitrogen, phosphorus and potassium) (S) 25:5:5:5 is generally recommended for optimum yield and quality of tea (Camellia sinensis). Non-judicious use of this inorganic fertilizer how...Inorganic fertilizer NPK (nitrogen, phosphorus and potassium) (S) 25:5:5:5 is generally recommended for optimum yield and quality of tea (Camellia sinensis). Non-judicious use of this inorganic fertilizer however acidifies the soils and pollutes the environment. Integrated soil fertility management (ISFM) which involves the combined use of organic and inorganic fertilizer is recommended for improved crop yield and soil health. An experiment was carried out to determine the effect of enriching cattle manure with different ratios of inorganic fertilizers (OM: NPKS at ratios 1:2 and 1:4), and rates on soil nutrient status, nitrogen uptake and yield of tea in the east of Rift Valley, Kenya. Enriching manures and organic manure up to a rate of 150 kg N/ha increased the level of P mature leaf. A higher N and K level in the mature leaf was observed when NPKS was applied at higher rates. In the soil, fertilizer rate up to 150 kg N/ha showed higher pH and K where organic manure and enriched manures were applied while NPKS treatment showed higher P content throughout the soil depths. Enriching organic manures with inorganic fertilizers increased yield significantly.展开更多
The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NP...The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NPK)) on chemical composition and dry matter in cassava (Manihot esculenta) organs (clone 1171) during harvest period. The pots experiment was laid out in randomised complete bloc design with five treatments and four replications. Water, nitrogen, potassium, phosphorus, sodium, total proteins and total lipids contents of the leaves, shoots and tubers were determined. After 9 months growing period, results showed that fertilizer types enriched with K, PK and NPK significantly increased the organic compounds contents of the leaves (P〈0.05). Furthermore, fertilizers with high phosphorus content significantly increased the lipid contents of the leaves (25%). Fertilizers enriched with NPK positively influenced the biomass partitioning in Manihot esculenta. Application of fertilizers enriched with NPK led to higher levels of total proteins in the leaves and tubers (70 mg g DM^-1 and 30 mg g DM^-1 respectively) compared to control (17 mg g DM^-1 and 9 mg g DM^-1 respectively). These results help to demonstrate the value of these fertilizers enrichment to improve the chemical composition and dry matter partitioning of cassava.展开更多
Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium (Se) concen- trations. A long-term (over 20 years) experimental field study, started in 1989, ...Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium (Se) concen- trations. A long-term (over 20 years) experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North China Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments: 1) organic compost (OC), 2) half organic compost plus half N-P-K chemical fertilizers (OC + NPK), 3) N-P-K fertilizers (NPK), 4) N-P fertilizers (NP), 5) P-K fertilizers (PK), 6) N-K fertilizers (NK), and 7) an un-amended control. Soil samples from the surface (20 cm) were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments (149 ± 8 beg kg-1) were higher than those in the soil samples collected in 1989 at the beginning of the experiment (112 4- 4 beg kg-1), and decreased in the order of OC 〉 OC + NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction (50.06%± 3.94%) was the dominant form of Se in the soil, followed by the residual fraction (24.12% ± 2.89%), exchangeable fraction (15.09% ± 4.34%) and Fe-Mn oxides fraction (10.73%±4.04%). With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer (0-20 cm) were mainly related to soil organic carbon (SOC), although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC + NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food (100 μg kg·1]. Additionallv. Se concentrations in grains were also decreased by the deficiencies of major soil nutrients, especially P.展开更多
Soil productivity is the ability of a soil, in its normal environment, to support plant growth and can be evaluated with respect to crop production in unfertilized soil within the agricultural ecosystem. Both soil pro...Soil productivity is the ability of a soil, in its normal environment, to support plant growth and can be evaluated with respect to crop production in unfertilized soil within the agricultural ecosystem. Both soil productivity and fertilizer applications affect crop yields. A long-term experiment with a winter wheat-summer maize rotation was established in 1989 in a field of the Fengqiu State Key Agro-Ecological Experimental Station, a region typical of the North China Plain, including seven treatments: 1) a balanced application of NPK chemical fertilizers (NPK); 2) application of organic fertilizer (OM); 3) application of 50% organic fertilizer and 50% NPK chemical fertilizers (1/2OMN); 4) application of NP chemical fertilizers (NP); 5) application of PK chemical fertilizer (PK); 6) application of NK chemical fertilizers (NK); and 7) unfertilized control (CK). To investigate the effects of fertilization practices on soil productivity, further pot tests were conducted in 2007-2008 using soil samples from the different fertilization treatments of the long-term field experiment. The soil sample of each treatment of the long-term experiment was divided into three pots to grow wheat: with no fertilization (Potunf), with balanced NPK fertilization (POtNPK), and with the same fertilizer(s) of the long-term field experiment (Potori). The fertilized soils of the field experiment used in all the pot tests showed a higher wheat grain yield and higher nutrient uptake levels than the unfertilized soil. Soil productivity of the treatments of the field experiment after 18 years of continuous fertilizer applications were ranked in the order of OM 〉 1/2OMN 〉 NPK 〉 NP 〉 PK 〉 NK 〉 CK. The contribution of soil productivity of the different treatments of the field experiment to the wheat grain yield of Potori was 36.0%-76.7%, with the PK and NK treatments being higher than the OM, 1/2OMN, NPK, and NP treatments since the soil in this area was deficient in N and P and rich in K. Wheat grain yields of PotNPK were higher than those of Potori and Potunf. The N, P, and K use efficiencies were higher in POtNPK than Potori and significantly positively correlated with wheat grain yield. Soil organic matter could be a better predictor of soil productivity because it correlated more strongly than other nutrients with the wheat grain yield of Potuf. Wheat yields of POtNPK showed a similar trend to those of Potunf, indicating that soil productivity improvement was essential for a further increase in crop yield. The long-term applications of both organic and chemical fertilizers were capable of increasing soil productivity on the North China Plain, but the former was more effective than the latter. The balanced application of NPK chemical fertilizers not only increased soil productivity, but also largely increased crop yields, especially in soils with lower productivity. Thus, such an approach should be a feasible practice for the sustainable use of agricultural soils on the North China Plain, particularly when taking into account crop yields, labor costs, and the limited availability of organic fertilizers.展开更多
基金Supported by Special Fund from Ministry of Agriculture for Scientific Research(200903025-05)~~
文摘Field plot experiment was conducted to study the effects of two slow-re- lease fertilizers and balanced fertilization on dry matter accumulation, yield, fertilizer use efficiency, nitrogen, phosphorus and potassium uptake of peppers at Jiangna Town, Yanshan County, Yunnan Province in 2011. The results showed that the dry matter accumulation in dried pepper plant, pepper yield, nitrogen, phosphorus, potassium uptake in peppers were significantly increased in all the fertilizer treat- ments, compared with those in control (no fertilizer). Compared with conventional fertilization, balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer significantly increased dried pepper economic output by 20.94%, 17.5% and 14.54%, nitrogen uptake in dried peppers by 21.53%,18.46% and 13.19%, phosphorus uptake in dried peppers by 14.08%, 15.76% and 10.44%, potassium uptake in dried peppers by 22.66%, 15.73% and 16.28%; they also in- creased nitrogen and potassium use efficiency, but reduced potassium use efficiency due to the increased potassium addition. In treatments with balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer, the nitrogen utiliza- tion was 5.84%, 7.14% and 8.33% higher and the phosphorus utilization was 3.32%, 3.27% and 2.47% higher than those in treatment with conventional fertiliza- tion. In addition, the nitrogen application could be reduced by 20%-50% by bal- anced fertilization and the two slow-release fertilizers, thereby reducing environmen- tal pollution. Slow-release fertilizers could also reduce the frequency of fertilization and labor costs.
文摘A 15-year field experiment was carried out in Henan Province, China, to study the effects of different fertilization practices on yield of a wheat-maize rotation. Fertilizers tested contained N alone (N), N plus P (NP) or plus P and K (NPK), all with or without manure (M). Different long-term fertilization practices affected the yields under the rotation system of wheat and maize differently and the effects on yields was in a general trend of MNPK>MNP>MN>NPK>NP>M>N>the control. The average contribution rate of soil fertility to the highest yield was 37.9%, and the rest 62.1% came from fertilizer applications. The yield effects of the chemical fertilizers were in the order of N>P>K and were increased by application of manure.Balanced fertilization with multielement chemical fertilizers and manure can be effective in maintaining growth in agricultural production. Combined application of chemical fertilizer and organic manure also increased the content of soil organic matter.
文摘A pot experiment was conducted to determine the dynamics of soil microbial biomass in a rainfed soil under wheat cultivation at the University of Arid Agriculture, Rawalpindi, Pakistan. The treatments applied were: 1) a control (CK), 2) NPK (0.44-0.26-0.18 g pot-1), 3) farmyard manure (FYM, 110 g pot-1), 4)poultry manure (PM, 110 g pot-1), 5) FYM (110 g pot-1) + NPK (0.44-0.26-0.18 g pot-1), 6) poultry manure (PM, 110 g pot-1) + NPK (0.44-0.26-0.18 g pot-1), 7) FYM (110 g pot-1) + NPK(S) (0.44-0.26-0.18 g pot-1, one half of the NPK at sowing and the other half one month after sowing), and 8) PM (110 g pot-1) + NPK(S) (0.44-0.26-0.18 g pot-1, one half of the NPK applied at sowing and the other half one month after sowing). The experiment was laid out using a completely randomized design with three replications. Microbial biomass C, N and P contents increased continuously from the beginning of the experiment up to the three-leaf stage. A slight decline was observed at the tillering stage in all treatments except with the organic manures + NPK(S) treatments. After tillering there was an increase in all treatments to the recorded maximum point at the full heading stage in all treatments except with the organic manures + NPK(S) treatments. In the FYM + NPK(S) and PM + NPK(S) treatments; however, there was a continuous increase in microbial biomass up to the heading stage. At the harvesting stage a sharp decline was noted in all treatments. The C:N ratio of microbial biomass in tested soil ranged from 7.8 to 11.3, while C:P ratio of microbial biomass in the tested soil ranged from 22.6 to 35.1 throughout all growth stages of the wheat crop.
文摘Twenty eight species of forage crops were planted on acid soils derived from Quaternary red clay (pH 4.16)and red sandstone (pH 4.55) to study genotypic differences of the forage crops in tolerance to acid soils as affected by liming, phosporus and potassium fertilizer application. Eight forage species, Lolium multiflorum L., Brachiaria decumbens, Digitaria sumtisii, Melinis minutiflora, Paspalum dilatatum, Paspalum wettsteinii,Sataria viridis Beanv and Shcep’s Festuca, were highly tolerant to acid soils, and grew relatively well in the tested soils without lime application, whereas most of the other 20 tested forage species such as Lolium perenne L., Meadow Festuca and Trifolium pratense L. were intolerant to acid soils, showing retarded growth when the soil pH was below 5.5 and significant increase in dry matter yields by phosphrus fertilizer application at soil pH 6.0. Results showed that large differences in tolerance to acid soils existed among the forage species,and tolerance of the forage species to acid soils might be closely associated with their tolerance to Al and P efficiency.
基金supported by the International Potash Institute.
文摘Over a period of two years , field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv. Lu-Bai 3), autumn greens (B. chinensis L., cv. Piao-Geng-Bai), winter greens (B. var. rosularis Tsen et Lee, cv. You-Dong-Er), and summer greens (B. chinensis L., cv. Zao-Shu 5), respectively. Each experiment included one CK treatment without K, N and P fertilizers applied, and four treatments with from low to high doses, 0-300 kg hm-2 for Chinese cabbage, 0-150 kg hm-2 for autumn and winter greens and 0-180 kg hm-2 for summer greens, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One treatment of K fertilizer in the form of muriate of potash (MOP) applied at high levels (150 or 180 kg hm-2) together with N and P fertilizers was included in the experiments of autumn, winter and summer greens , respectively, in order to compare the effects of SOP and MOP. The market yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. K fertilization increased not only K contents but also the amounts of N, P and K absorbed in shoots of autumn, winter and summer greens, which were statistically significantly correlated to their yields. It can also be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased. As compared to MOP, SOP was more effective on the yields and quality of autumn, winter and summer greens at the high levels of fertilization.
文摘Generally, the diameter of organic melon fruit relatively short (the fruit is small), weight of fruit just as big as 1.25-1.49 kg only, while weight of inorganic melon fruit can reach 2-3 kg. The research was conducted by experiment method with the aim to enhance quality of the organic melon fruit. Experiment I is: N, P and K fertilizer solution concentration as main plot (0, 20, 30, and 40 g L^-1) and dose of cow manure fertilizer as sub plot (0, 10, 15, and 20 ton hal) (there are 16 treatment combinations). Experiment II is kinds of dung as main plot (chicken, cow, and goat) and dose of fertilizer as sub plot (20, 25, and 30 ton hat) (there are 9 treatment combinations). Experiment III is dose of cow manure fertilizer as main plot (15, 20, 25, and 30 ton hal) and gibberellins concentration as sub plot (0, 30, 60, and 120 ppm) and (there are 16 treatment combinations). Each of the treatment combination replicated 3 times. The result showed that chicken, cow, and goats manure can be used in organic cultivation of melons, and cow manure has the highest potential. The role of the dose is relatively low in plant growth, but to improve the quality of fruit need dose of 10-15 tons hat. The addition of inorganic NPK fertilizer solution or use of gibberellins can increase growth and fruit quality of melon (the used of gibberellins are recommended).
文摘Inorganic fertilizer NPK (nitrogen, phosphorus and potassium) (S) 25:5:5:5 is generally recommended for optimum yield and quality of tea (Camellia sinensis). Non-judicious use of this inorganic fertilizer however acidifies the soils and pollutes the environment. Integrated soil fertility management (ISFM) which involves the combined use of organic and inorganic fertilizer is recommended for improved crop yield and soil health. An experiment was carried out to determine the effect of enriching cattle manure with different ratios of inorganic fertilizers (OM: NPKS at ratios 1:2 and 1:4), and rates on soil nutrient status, nitrogen uptake and yield of tea in the east of Rift Valley, Kenya. Enriching manures and organic manure up to a rate of 150 kg N/ha increased the level of P mature leaf. A higher N and K level in the mature leaf was observed when NPKS was applied at higher rates. In the soil, fertilizer rate up to 150 kg N/ha showed higher pH and K where organic manure and enriched manures were applied while NPKS treatment showed higher P content throughout the soil depths. Enriching organic manures with inorganic fertilizers increased yield significantly.
文摘The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NPK)) on chemical composition and dry matter in cassava (Manihot esculenta) organs (clone 1171) during harvest period. The pots experiment was laid out in randomised complete bloc design with five treatments and four replications. Water, nitrogen, potassium, phosphorus, sodium, total proteins and total lipids contents of the leaves, shoots and tubers were determined. After 9 months growing period, results showed that fertilizer types enriched with K, PK and NPK significantly increased the organic compounds contents of the leaves (P〈0.05). Furthermore, fertilizers with high phosphorus content significantly increased the lipid contents of the leaves (25%). Fertilizers enriched with NPK positively influenced the biomass partitioning in Manihot esculenta. Application of fertilizers enriched with NPK led to higher levels of total proteins in the leaves and tubers (70 mg g DM^-1 and 30 mg g DM^-1 respectively) compared to control (17 mg g DM^-1 and 9 mg g DM^-1 respectively). These results help to demonstrate the value of these fertilizers enrichment to improve the chemical composition and dry matter partitioning of cassava.
基金supported by the National Basic Research Program (973 Program) of China (No.2011CB100506)the China Agriculture Research System-Wheat (No.CARS-03-02A)the Knowledge Innovation Program of Chinese Academy of Sciences (No.KSCX2-EW-N-08)
文摘Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium (Se) concen- trations. A long-term (over 20 years) experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North China Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments: 1) organic compost (OC), 2) half organic compost plus half N-P-K chemical fertilizers (OC + NPK), 3) N-P-K fertilizers (NPK), 4) N-P fertilizers (NP), 5) P-K fertilizers (PK), 6) N-K fertilizers (NK), and 7) an un-amended control. Soil samples from the surface (20 cm) were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments (149 ± 8 beg kg-1) were higher than those in the soil samples collected in 1989 at the beginning of the experiment (112 4- 4 beg kg-1), and decreased in the order of OC 〉 OC + NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction (50.06%± 3.94%) was the dominant form of Se in the soil, followed by the residual fraction (24.12% ± 2.89%), exchangeable fraction (15.09% ± 4.34%) and Fe-Mn oxides fraction (10.73%±4.04%). With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer (0-20 cm) were mainly related to soil organic carbon (SOC), although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC + NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food (100 μg kg·1]. Additionallv. Se concentrations in grains were also decreased by the deficiencies of major soil nutrients, especially P.
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences (Nos. KZCX2-YW-312 and KZCX2-YW-406-2)the National Natural Science Foundation of China (No. 40621001)
文摘Soil productivity is the ability of a soil, in its normal environment, to support plant growth and can be evaluated with respect to crop production in unfertilized soil within the agricultural ecosystem. Both soil productivity and fertilizer applications affect crop yields. A long-term experiment with a winter wheat-summer maize rotation was established in 1989 in a field of the Fengqiu State Key Agro-Ecological Experimental Station, a region typical of the North China Plain, including seven treatments: 1) a balanced application of NPK chemical fertilizers (NPK); 2) application of organic fertilizer (OM); 3) application of 50% organic fertilizer and 50% NPK chemical fertilizers (1/2OMN); 4) application of NP chemical fertilizers (NP); 5) application of PK chemical fertilizer (PK); 6) application of NK chemical fertilizers (NK); and 7) unfertilized control (CK). To investigate the effects of fertilization practices on soil productivity, further pot tests were conducted in 2007-2008 using soil samples from the different fertilization treatments of the long-term field experiment. The soil sample of each treatment of the long-term experiment was divided into three pots to grow wheat: with no fertilization (Potunf), with balanced NPK fertilization (POtNPK), and with the same fertilizer(s) of the long-term field experiment (Potori). The fertilized soils of the field experiment used in all the pot tests showed a higher wheat grain yield and higher nutrient uptake levels than the unfertilized soil. Soil productivity of the treatments of the field experiment after 18 years of continuous fertilizer applications were ranked in the order of OM 〉 1/2OMN 〉 NPK 〉 NP 〉 PK 〉 NK 〉 CK. The contribution of soil productivity of the different treatments of the field experiment to the wheat grain yield of Potori was 36.0%-76.7%, with the PK and NK treatments being higher than the OM, 1/2OMN, NPK, and NP treatments since the soil in this area was deficient in N and P and rich in K. Wheat grain yields of PotNPK were higher than those of Potori and Potunf. The N, P, and K use efficiencies were higher in POtNPK than Potori and significantly positively correlated with wheat grain yield. Soil organic matter could be a better predictor of soil productivity because it correlated more strongly than other nutrients with the wheat grain yield of Potuf. Wheat yields of POtNPK showed a similar trend to those of Potunf, indicating that soil productivity improvement was essential for a further increase in crop yield. The long-term applications of both organic and chemical fertilizers were capable of increasing soil productivity on the North China Plain, but the former was more effective than the latter. The balanced application of NPK chemical fertilizers not only increased soil productivity, but also largely increased crop yields, especially in soils with lower productivity. Thus, such an approach should be a feasible practice for the sustainable use of agricultural soils on the North China Plain, particularly when taking into account crop yields, labor costs, and the limited availability of organic fertilizers.