Molybdenum and Cobalt Application in Bean （Phaseolus vulgaris L.） with Two Fertilization Systems under No-Tillage

Molybdenum （Mo） and Cobalt （Co） play an important role in nitrogen （N） metabolism of grain legumes. Their applications to alkaline soils have been scarcely studied. A field experiment was set up to evaluate the Mo and Co application in common bean cv. Canario Centenario under two fertilization systems： inorganic fertilization and inoculation with Rhizobium etli. In each system, Mo and Mo ＋ Co were applied by seed impregnation at doses of 1.36 g/kg of seed for Mo and 0.26 g/kg of seed for Co; a control for each fertilization system and an absolute control were included. Yield components, nodules characteristics and N content by grains and foliage were evaluated. A completely randomized block design with seven treatments and five replications was used. Mo application increased the grain yield, grain size, nodulation and N accumulation in grains under both fertilization systems. Mo increased the total N uptake by the plant in 35.4% and 26%, for N fertilized and inoculated plants, respectively. Co application increased only nodules number and weight, and N content under inoculation. Mo application to beans cultivated in alkaline soils is recommended, but Co application is suitable only when beans are inoculated with rhizobia.

Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19

The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.

Variable rate fertilization system with adjustable active feed-roll length

This paper presented a novel variable rate fertilization system based on the method of adjusting the active feed-roll length of a fluted roller.The feasibility of this method was discussed using analysis of the fluted roller model.One seed drill produced by Kuhn Company(France),which could sow and fertilize simultaneously,was used as a test platform to implement the mechanical structure of variable rate fertilization.The design methods for the variable rate fertilization mechanical structure and actuator were introduced in detail.A low-cost and stable embedded support decision subsystem and corresponding software were developed.The support decision subsystem is based on grid management.Each grid field cell contains information about corresponding spatial position and fertilizer application rate.A SpatiaLite database was employed to solve the spatial location search and spatial data query.Experiments were conducted to evaluate the fertilization uniformity and dynamic response time.The average value of coefficient of variation is 8.4%in five different active feed-roll lengths which reflects good uniformity.The dynamic response times for the adjustment of variable rate fertilization system from 204 kg/hm^(2) to 319 kg/hm^(2) and 319 kg/hm^(2) to 204 kg/hm^(2) are about 4.2 s.The results suggest that the variable rate fertilization system performs well in dynamic adjustment and stability.

A Field Study on Effects of Nitrogen Fertilization Modes on Nutrient Uptake,Crop Yield and Soil Biological Properties in Rice-Wheat Rotation System

Rational application of nitrogen （N） fertilizers is an important measure to raise N fertilizer recovery rate and reduce N loss.A two-year field experiment of rice-wheat rotation was employed to study the effects of N fertilization modes including a N fertilizer reduction and an organic manure replacement on crop yield,nutrient uptake,soil enzyme activity,and number of microbes as well as diversity of microbes.The result showed that 20% reduction of traditional N fertilizer dose of local farmers did not significantly change crop yield,N uptake,soil enzyme activity,and the number of microbes （bacteria,actinomycetes,and fungi）.On the basis of 20% reduction of N fertilizer,50% replacement of N fertilizer by organic manure increased the activity of sucrose,protease,urease,and phosphatase by 46-62,27-89,33-46,and 35-74%,respectively,and the number of microbes,i.e.,bacteria,actinomycetes,and fungi by 36-150,11-153,and 43-56%,respectively.Further,organic fertilizer replacement had a Shannon＇s diversity index （H） of 2.18,which was higher than that of other modes of single N fertilizer application.The results suggested that reducing N fertilizer by 20% and applying organic manure in the experimental areas could effectively lower the production costs and significantly improve soil fertility and biological properties.

Carbon Sequestration in Soil Humic Substances Under Long-Term Fertilization in a Wheat-Maize System from North China

The changes in humic substances （HS） is fundamental in detecting soil carbon sequestration mechanisms in natural and cultivated environments. Based on a long-term trial, the amounts of water dissolved substances （WSS）, humic acid （HA）, fulvic acid （FA） and humin （HU） were determined to explore the impact of long-term fertilization on HS. Increases in the amounts of WSS, HA, FA and HU were significant different among the treatments with manure. A significant correlation was found between the increased soil organic carbon （SOC） and HS （R^2=0.98, P〈0.01）. The change in the E4/E6 ratio was significantly correlated with the increased SOC （R2=0.88, P〈0.01）, HA （R^2=0.91, P〈0.01）, FA （R^2=0.91, P〈0.01） and HU （R^2=0.88, P〈0.01）. The cluster was mainly divided into two parts as manure fertilization and inorganic fertilization, based on the increases in HA, FA and HU. These results suggest that long term fertilization with manure favours carbon sequestration in HS and is mainly stabilized as HU, while the HA becomes more aliphatic. We conclude that increases in SOC can be linked to changes in the molecular characteristics of HS fractions under long term fertilization.

Fertilization for High Yields in Corn-Sweet Potato-Wheat Rotation: A Systematic Approach to Nutrient Limiting Factors of Soils in Chongqing, China

A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet potato and wheat in rotation. The results showed that N, P and K were deficient in both soils, Cu, Mn, S andZn in the gray-brown purple soils and Ca, Mg, Mo and Zn for the yellow soils. Balanced fertilizer application increased yields of corn, sweet potato and wheat by 28.4%, 28.7% and 4.4%, respectively, as compared to the local farmers' practice. The systematic approach can be considered as one of the most efficient and reliable methods in fertility study.

Wolfberry tree dual-model detection method and orchard target-oriented fertilization system based on photoelectric sensors

Orchard target-oriented fertilizing with on-board sensor technology can improve fertilizer efficiency and reduce environmental pollution.Photoelectric sensors are widely used for object detection because of their low cost and fast response time.This paper presents a Wolfberry tree dual-model detection method and the design of an orchard target-oriented variable-rate fertilization system based on photoelectric sensors.The dual-model detection method includes the Trunk Detection Model(TDM)and Canopy Detection Model(CDM),which can be applied for Wolfberry orchards at the green cluster and mature stages,respectively.A target-oriented fertilization system was designed using the dual-model method,and tested in the lab and Chinese Wolfberry orchard.The laboratory test results showed that the average center offset distances on the condition of detecting trunks,continuous canopies,and discontinuous canopies were 4.1 cm,9.1 cm and 13.1 cm,respectively.The system could ignore the signals from canes when their diameters were less than 16 mm,and also could determine the gaps within a tree when they were less than 21 cm.The orchard test results showed that the system accomplished target-oriented fertilization 95 times for 92 trees at the mature stage.The results indicated that the dual-model detection method could be used for Wolfberry trees or other trees with similar canopy changes at different growth stages.

Design and experiment of vertical pneumatic fertilization system with spiral Geneva mechanism

In the traditional fertilization method,a large amount of fertilizer is applied,which causes congestion easily.It is not conducive to the sustainable development of agriculture.In this work,a vertical pneumatic fertilization system with a spiral Geneva mechanism was designed according to the operational requirements of variable-rate and smooth fertilization.The uniformity in discharging fertilizer with different spiral angles was simulated and analyzed by extended discrete element method(EDEM)based simulation software,from where the spiral angle of the fertilizer discharge wheel was determined to be 45°.The fertilization system includes a fertilizer apparatus with a spiral Geneva mechanism,whose optimal performance parameters were obtained from the bench experiment.The accuracy and uniformity of the fertilizer application system were taken as the evaluation indicators.The linear relationships of the discharged amount of fertilizer with the rotational speed and the opening of the fertilizer discharging wheel were verified by both static blowing fertilization and field experiments.The static blowing experimental results show that the discharged amount of fertilizer has a high linear correlation and accuracy with both the opening and rotational speed,and the highest correlation occurs with the rotational speed.The rotational speed and opening have significant effects on the discharged amount of fertilizer and the average coefficient of variation.The effect of the rotational speed was the most significant.According to the model obtained by multiple regression fittings,the optimal parameters were determined when the average coefficient of variation was small,the rotational speed was 15.9 r/min and the opening was 34.4 mm.Therefore,the purpose of precise fertilization can be achieved by adjusting the opening or rotational speed in a way to get the exact amount of fertilizer discharged as required by the corresponding crops.The field experiment showed that the variation coefficient of each fertilizer discharged decreases first and then increases with an increasing opening under different rotational speeds,which is consistent with the theoretical value.When the opening was 40 mm or 50 mm,the variation coefficient reached the minimum value,which is far less than the qualified index of 7.8%.In the static blowing experiment and the dynamic field experiment,the stability of the fertilizer discharging device can be significantly enhanced with the utilization of the pneumatic conveying fertilizer.This study can provide a theoretical reference for parameter selection and optimization of vertical spiral fertilization systems.

Changes in soil organic carbon pools following long-term fertilization under a rain-fed cropping system in the Loess Plateau,China

Understanding the mechanism of soil organic carbon(SOC)sequestration is of paramount importance in sustaining crop productivity and mitigating climate change.Long-term trials were employed to investigate the responses of total SOC and its pools,i.e.,mineral-associated OC(MOC),particulate OC(POC,containing Light-POC and Heavy-POC),to fertilization regimes at Yangling(25-year),Tianshui(35-year)and Pingliang(37-year)under a rain-fed cropping system in the Loess Plateau.The fertilization regimes in each trial included three treatments,i.e.,control(no nutrient input,CK),chemical fertilizers(CF),and organic manure plus chemical fertilizers(MCF).Relative to the CK,long-term fertilization appreciably increased SOC storage by 134,89 and 129 kg ha^(–1)yr^(–1)under CF,and 418,153 and 384 kg ha^(–1)yr^(–1)under MCF in plough layer soils(0–20 cm),respectively,at the Yangling,Tianshui and Pingliang sites.The MOC pools accounted for 72,67 and 64%of the total SOC at the above three sites with sequestration rates of 76,57 and 83 kg ha^(–1)yr^(–1)under CF and 238,118 and 156 kg ha^(–1)yr^(–1)under MCF,respectively.Moreover,the MOC pool displayed a saturation behavior under MCF conditions.The POC accordingly constituted 27,33 and 36%of SOC,of which Light-POC accounted for 11,17 and 22%and Heavy-POC for 17,16 and 15%of SOC,respectively.The sequestration rates of POC were 58,32 and 46 kg ha^(–1)yr^(–1)under CF,and 181,90 and 228 kg ha^(–1)yr^(–1)under MCF at the three respective sites,in which Light-POC explained 59,81 and 72%of POC under CF,and 60,40 and 69%of POC under MCF,with Heavy-POC accounting for the balance.Compared with CK,the application of CF alone did not affect the proportions of MOC or total POC to SOC,whereas MCF application markedly reduced the proportion of MOC and increased the POC ratio,mainly in the Light-POC pool.The distribution of SOC among different pools was closely related to the distribution and stability of aggregates.The present study confirmed that organic manure amendment not only sequestered more SOC but also significantly altered the composition of SOC,thus improving SOC quality,which is possibly related to the SOC saturation level.

Interactions between phosphorus availability and microbes in a wheat–maize double cropping system:A reduced fertilization scheme

Mechanisms controlling phosphorus(P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood.In the present study,we conducted a pot experiment for four consecutive wheat–maize seasons(2016–2018) using calcareous soils with high(30.36 mg kg^(–1)) and low(9.78 mg kg^(–1)) initial Olsen-P content to evaluate the effects of conventional P fertilizer application to both wheat and maize(Pwm) along with a reduced P fertilizer application only to wheat(Pw).The microbial community structure along with soil P availability parameters and crop yield were determined.The results showed that the Pw treatment reduces the annual P input by 33.3% without affecting the total yield for at least two consecutive years as compared with the Pwm treatment in the high Olsen-P soil.Soil water-soluble P concentrations in the Pw treatment were similar to those in the Pwm treatment at the 12-leaf collar stage when maize requires the most P.Furthermore,the soil P content significantly affected soil microbial communities,especially fungal communities.Meanwhile,the relative abundances of Proteobacteria and alkaline phosphatase(ALP) activity of Pw were significantly higher(by 11.4 and 13.3%) than those of Pwm in soil with high Olsen-P.The microfloral contribution to yield was greater than that of soil P content in soil with high Olsen-P.Relative abundances of Bacillus and Rhizobium were enriched in the Pw treatment compared with the Pwm treatment.Bacillus showed a significant positive correlation with acid phosphatase(ACP) activity,and Rhizobium displayed significant positive correlations with ACP and ALP in soil with high Olsen-P,which may enhance P availability.Our findings suggested that the application of P fertilization only to wheat is practical in high P soils to ensure optimal production in the wheat and maize double cropping system and that the soil P availability and microbial community may collaborate to maintain optimal yield in a wheat–maize double cropping system.

Effects of Different Culture Systems on In Vitro Fertilization of Oocyte in Bovine

[ Objective] To investigate the optimal culture system for in vitro fertilization （IVF） of oocyte in bovine. [ Method] The IVF of mature bovine oocytes was conducted and the fertilized eggs were cultured in vitro with different culture systems. In the traditional culture system, the TALP medium and BO medium were used as fertilization medium, respectively; and M-199 medium supplemented with 5% FCS was used as fertilized egg culture medium. In the transitional culture system, the TALP medium and BO medium were used as fertilization medium; 60% TALP and 40% M-199 supplemented with 5% FCS and 60% BO and 40% M-199 supplemented with 5% FCS were used as fertilized egg culture medium, respectively. The effects of different culture systems on fertilization rate and cleavage rate were observed. E Result] In the transitional culture system （with TALP medium as fertilization medium and with 60% TALP and 40% M-199 supplemented with 5% FCS as fertilized egg culture medium）, the fertilization rate and cleavage rate were increased to 77.8% and 55.6%, respectively. [ Conclusion] The transitional culture system （with TALP medium as fertilization medium and with 60% TALP and 40% M-199 supplemented with 5% FCS as fertilized egg culture medium） is the optimal culture system for IVF of bovine oocyte.

Research on Index System for Luffa(Luffa acutangula Roxb.) Fertilization in Foshan

On basis of “3414” experiment, regression analysis was conducted on rel- ative yield and fertilizer quant;.ty, and a regression equation was established, as fol- lows： Y=I 699,09 ＋52.89N -3i82P ＋59.27K-1.17N2 -0.11 p2 ＋0.06K2 ＋2.02NP-2.16NK- 1.97PK （FF=0,98）. The results of regression analysis showed F〉F0.05, indicating that fertilizer quantity is of significant regression relationship with yield. It was analyzed that yield-increasing range of N fertilizer was directly proportional to fertilizer quanti- ty, and negative yield even occurs if excessive P fertilizer is applied. In general, fertilizer effects from high to low were N fertilizer〉K ferUlizer〉P fertilizer. Besides, on equation aralysls, it was proposed the optimal fertilizer quantities included N fertilizer （N） of 270 kg, P fertilizer （PUs） of 165 kg and K fertilizer （K20） of 225 kg for achieving ideal yield of 2 500 kg/hm2 of luffa in Foshan. Key words Foshan; Luffa; Index system of fertilization; Efficiency analysis

Research on the Behavior and Egg Fertilization Rate of Dwarf Layers and White Leghorn Chickens Fed in Floor-Rearing System

Influenced by animal welfare requirements and expensive labor cost, producers tend to feed layers in non-cage system such as floor rearing. With the development of commercial lines of dwarf layers, the property of dwarf layers＇ natural mating is drawing more and more attention. In this study, the authors hybridized Nongda Ill dwarf layers with White Leghorn chickens in floor-rearing system to research whether dwarf layers had defect in natural mating. Two steps of experiments were performed. The authors detected the fertilization rate of collected eggs, observed chickens＇ behavior in step I when a hen from other group was suddenly put into and recorded copulation number of every group in step II from 7：30 to 19：30. The results indicated that drawf cocks were as good as Leghorn cocks in natrual mating under floor-rearing system while drawf hens were better than Leghorn hens. Observation results showed no difference on reaction to intermixed hens between drawf layers and Leghorn layers. The best proportion of male to female for drawf layers was 1：8 in this experiment and dwarf cocks tended to mate dwarf hens rather than Leghorn hens.

Comparison of the Index System of Ecological Balanced Fertilization for Three Crops

This paper conducted comparative study of the index system of ecological balanced fertilization for rice,wheat and maize by data mining method based on data of"3414 fertilizer field trials"of rice,wheat and maize by published papers from national soil testing and recommendation since 2005.The main conclusions of this paper were as follow:①since the three crops all belonged to Gramineae,they were consistent in variation trends of fertilizer utilization ratio,nutrient conversion rate,relative abundance-deficiency value of soil nutrient,optimum fertilization amount in most cases.②Due to the influence of the economic production,biological production,different water conditions in paddy field and dry farmland,length of growing season,cropping system(one year before and after the rotation)and so on,sometimes the laws of four aspects above mentioned for the three crops had opposite and gradient variations.

Studies on the Provincial-level Index System of Ecological Balanced Fertilization for Rice in China

In this paper,the index system of ecological balanced fertilization for rice was discussed by data mining method based on this column.Three aspects of provincial average,typical province and all samples were studied,and the results and conclusions were as follows:①climate condition was one of the main factors of soil formation,which was also an important basis for the division of rice growing areas.The proportion of available nutrients was different in different rice growing areas.This was the result of long-term climate and man-made action,which constituted the basic fertility pattern of soil available nutrients for rice in China.②One of the basic fertility indexes of rice soil in China was the proportion of available nutrients,which was the theoretical basis for adjusting the proportion of N,P and K fertilizers.③Although the total amount and proportion of available nutrients in different rice growing areas were different,they can be adjusted to the optimum absorption ratio of rice by fertilizing measures,so as to achieve the goal of ecological balanced fertilization such as high production and good quality.④The basic soil nutrient index of more than 8000 kg/hm 2 of rice production was more than 5 of available K/available P.

Theoretical Analysis on Index System of Ecological Balanced Fertilization for Three Crops

This paper analyzed theoretical basis of ecological balanced fertilization by data mining method based on the relationships among relative abundance-deficiency values of soil nutrients,optimum fertilization amounts and nutrient conversion rates of N,P and K for rice,wheat and maize in column papers.The results and conclusions were as follows:①the scientific basis of guiding fertilization by the relative abundance-deficiency value of soil nutrient was insufficient.②The scientific basis for predicting fertilizer amount according to nutrient conversion rate was sufficient.③There was consistency among the relative abundance-deficiency values of soil nutrients,indicating that the soil nutrient balance was important to the production.④There was some consistency among the optimum fertilizer amounts,indicating that N,P and K fertilizer should be balanced.⑤There was some consistency among nutrient conversion rates,indicating that nutrient uptake was consistent,which required the consistency among relative abundance-deficiency values of soil nutrients.When there was inconsistency,it needed to be supplemented by means of fertilization.⑥The relative abundance-deficiency value of soil nutrient and optimum fertilizer amounts of other nutrients were negatively correlated mostly,indicating that if the relative abundance-deficiency value of soil nutrient was high,the others also should be high,resulting in optimum fertilizer amounts of other nutrients decreased.⑦The nutrient conversion rate was negatively correlated mostly with the optimal fertilizer amounts of other nutrients,indicating that more fertilizer amount of one nutrient lowered its own conversion rate,mean while also reduced the conversion rates of other nutrients.It embodied the unity and balance of nutrient absorption by the crops.

Specific Index System of Ecological Balanced Fertilization for Maize

This paper studied the index system of ecological balanced fertilization for maize by data mining method based on data of"3414 fertilizer field trials"of maize by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows.①Soil nutrient content could not be used as indicator of fertilizer application of maize.②The conceptual model of N conversion rate of maize for plot was Y N≈a+b×optimum production-c×optimum fertilizer amount of N-d×optimum phosphorus application amount-e×optimum potassium application amount-f×temperature in growth season-g×rainfall in growth season.The conceptual model of P conversion rate of maize for plot was Y P≈a+b×optimum phosphorus application amount-c×optimum nitrogen application amount-d×optimum potassium application amount.The conceptual model of K conversion rate of maize for plot was Y K≈a+b×optimum yield-c×optimum nitrogen application amount-d×optimum phosphorus application amount-e×optimum potassium application amount-f×temperature in growth season-g×rainfall in growth season.③The conceptual model of the optimum fertilizer amount of N of maize for plot was Y N≈a+b×optimum phosphorus application amount+c×optimum potassium application amount+d×temperature in growing season+e×rainfall in growing season,and the conceptual model of the optimum fertilizer amount of P was Y P≈a+b×optimum nitrogen application amount,and the conceptual model of the optimum fertilizer amount of K was Y K≈a+b×optimum nitrogen application amount+c×temperature in growth season+d×rainfall in growth season-e×optimum yield.④The conceptual model of relative abundance-deficiency value of soil N of maize for plot was that Y N≈a,and the conceptual model of relative abundance-deficiency value of soil P was Y P≈a,and the conceptual model of relative abundance-deficiency value of soil K was Y K≈a+b×optimum nitrogen application amount+c×optimum phosphorus application amount.

Specific Index System of Ecological Balanced Fertilization for Rice

This paper studied the nitrogen index system of ecological balanced fertilization for rice by data mining method based on data of"3414 fertilizer field trials"of rice by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows.①Soil nutrient content could not be used as fertilization indicator of rice.②The conceptual model of nitrogen conversion rate of rice for plot was Y N≈a+b×optimum production-c×optimum nitrogen fertilization amount-d×optimum phosphorus fertilization amount,and the conceptual model of phosphorus conversion rate was Y P≈a-b×optimum phosphorus fertilization amount-c×optimum potassium fertilization amount,and the conceptual model of potassium conversion rate was Y K≈a+b×optimum production+c×optimum nitrogen fertilization amount-d×optimum potassium fertilization amount-e×annual average precipitation.③The conceptual model of the optimum nitrogen fertilization amount of rice for plot was Y N≈a+b×optimum production+c×optimum phosphorus fertilization amount-d×annual average precipitation,and the conceptual model of the optimum phosphorus fertilization amount was Y P≈a+b×optimum nitrogen fertilization amount+c×optimum potassium fertilization amount,and the conceptual model of the optimum potassium fertilization amount was Y K≈a+b×optimum phosphorus fertilization amount+c×annual average precipitation.④The conceptual model of relative abundance-deficiency value of soil nitrogen of rice for plot was Y N≈a-b×optimum nitrogen fertilization amount-c×optimum potassium fertilization amount,and the conceptual model of relative abundance-deficiency value of soil phosphorus was Y P≈a+b×soil available potassium-c×optimum potassium fertilization amount,and the conceptual model of relative abundance-deficiency value of soil potassium of rice was Y K≈a-b×optimum potassium fertilization amount.

Studies on the Provincial-level Index System of Ecological Balanced Fertilization for Wheat in China

In this paper,the index system of ecological balanced fertilization for wheat was discussed by data mining method based on this column.Three aspects of provincial average,typical province and all samples were studied,the results and conclusions were as follows:①climate condition was one of the main factors of soil formation,which was also an important basis for the division of wheat producing areas.The proportion of available nutrients was different in different wheat producing areas.This was the result of long-term climate and man-made action,and it constituted the basic fertility pattern of soil available nutrient for wheat in China.②One of the basic fertility indexes of soil for wheat in China was the proportion of available nutrients,which was the theoretical basis for adjusting the proportion of N,P and K fertilizers.③Although the total amount and proportion of available nutrients in different wheat producing areas were different,they can be adjusted to the optimum absorption ratio of wheat by fertilizing measures,so as to achieve the goal of ecological balanced fertilization such as high production and good quality.④The basic soil nutrient indexes of more than 5000 kg/hm 2 of wheat production were less than 6 of hydrolysable N/available P and less than 7 of available K/available P,and the fertilization index was that optimum K fertilization amount was 0.6-1.2 times of optimum P fertilization amount.

Studies on the Provincial-level Index System of Ecological Balanced Fertilization for Maize in China

In this paper,the index system of ecological balanced fertilization of maize was discussed by data mining method based on this column.Three aspects of provincial average,typical province and all samples were studied,and the results and conclusions were as follows:①climate condition was one of the main factors of soil formation,which was also an important basis for the division of maize producing areas.The proportion of available nutrients was different in different maize producing areas.This was the result of long-term climate and man-made action,which constituted the basic fertility pattern of soil available nutrient for maize in China.②One of the basic fertility indexes of maize soil in China was the proportion of available nutrients,which was the theoretical basis for adjusting the proportion of N,P and K fertilizers.③Although the total amount and proportion of available nutrients in different maize producing areas were different,they can be adjusted to the optimum absorption ratio of maize by fertilizing measures,so as to achieve the goal of ecological balanced fertilization such as high production and good quality.④The basic soil nutrient index of more than 9000 kg/hm 2 of maize production was less than 8 of hydrolysable N/available P,and the fertilization index was that optimum N fertilization amount was more than 0.8 times of optimum P fertilization amount.