Environmental impacts and economic demands are driving the development of variable rate fertilization(VRF)technology for precision agriculture.Despite the advantages of a simple structure,low cost and high efficiency,...Environmental impacts and economic demands are driving the development of variable rate fertilization(VRF)technology for precision agriculture.Despite the advantages of a simple structure,low cost and high efficiency,uneven fertilizer-spreading uniformity is becoming a key factor restricting the application of centrifugal fertilizer spreaders.Accordingly,the particle application characteristics and variation laws for centrifugal VRF spreaders with multi-pass overlapped spreading needs to be urgently explored,in order to improve their distribution uniformity and working accuracy.In this study,the working performance of a self-developed centrifugal VRF spreader,based on real-time growth information of rice and wheat,was investigated and tested through the test methods of using the collection trays prescribed in ISO 5690 and ASAE S341.2.The coefficient of variation(CV)was calculated by weighing the fertilizer mass in standard pans,in order to evaluate the distribution uniformity of spreading patterns.The results showed that the effective application widths were 21.05,22.58 and 23.67 m for application rates of 225,300 and 375 kg/ha,respectively.The actual fertilizer application rates of multi-pass overlapped spreading were generally higher than the target rates,as well as the particle distribution CVs within the effective spreading widths were 11.51,9.25 and 11.28%for the respective target rates.Field test results for multi-pass overlapped spreading showed that the average difference between the actual and target application was 4.54%,as well as the average particle distribution CV within the operating width was 11.94%,which met the operation requirements of particle transverse distribution for centrifugal fertilizer spreaders.The results and findings of this study provide a theoretical reference for technical innovation and development of centrifugal VRF spreaders and are of great practical and social significance for accelerating their application in implementing precision agriculture.展开更多
[Objective] China is the world＇s largest fertilizer consumer. Fertilizer plays an important role in maintaining China＇s food security. Along with population and economic growth, overuse of fertilizers has caused ser...[Objective] China is the world＇s largest fertilizer consumer. Fertilizer plays an important role in maintaining China＇s food security. Along with population and economic growth, overuse of fertilizers has caused serious environmental problems, such as soil acidification, decline in soil organic carbon, and agricultural non-point source pollution. This study aimed to analyze the factors influencing farmers＂ decision making on fertilizer use, and provide policy recommendations on ways to affect fertilization. [Method] An econometric model reflecting fertilization of rural households was estimated from a survey distributed to 1 043 households randomly selected from 19 provinces in China. [Result] Results of the study showed that education years of fertilizer decision maker, fertilizer quality, organic fertilizer application, fertilizer price, and agricultural product price had significant effects on the fertilizer application rate at 1% level. Soil nutrient affected the fertilizer application rate at 10% level. [Conclusion] Policies aimed at improving the reasonable use of fertilizer should focus on the regulation of chemical fertilizer price, foundation of the organic-inorganic fertilizer system, soil testing, formulated fertilization, and agricultural extension service.展开更多
Excessive fertilizer application is common in the management of winter wheat (Triticum aestivum L.) in northwest China. However, this practice does not necessarily guarantee higher wheat yield and also causes a waste ...Excessive fertilizer application is common in the management of winter wheat (Triticum aestivum L.) in northwest China. However, this practice does not necessarily guarantee higher wheat yield and also causes a waste of resources and environmental pollution. The nitrogen (N), phosphorus (P), and potassium (K) fertilizer application rates need to be optimized to reduce the nitrate residue in the soil while maintaining a high wheat yield. Field experiments were conducted in three consecutive growth seasons (2018-2021) on winter wheat in Northern Xinjiang of China with four reduced fertilization (N-P_(2)O_(5)- K_(2)O) rates (FS1: 166-80-30 kg/hm^(2), FS2: 0-80-30 kg/hm^(2), FS3: 166-0-30 kg/hm^(2), FS4: 166-80-0 kg/hm^(2)) and the local fertilization rate (CK: 240-105-38). The soil nutrients, nutrient uptake content of organ, dry matter accumulation, yield, and fertilization use efficiency were investigated. The results showed increasing NH_(4)^(+)-N concentrations in the soil over the three growing seasons, while NO_(3)^(-)-N concentrations decreased in the later experimental years. High soil NH_(4)^(+)-N concentration and low soil NH_(4)^(+)-N residues were observed in FS3. When the control fertilization (CK) was applied, the grains had a higher proportion of N and P, while the N content in grains was relatively low at the high fertilization rate. When the fertilizer supply was insufficient (FS2, FS3, and FS4), the proportion of vegetative organs to the total biomass was relatively low. Lower fertilization rates resulted in higher N, P, and K use efficiencies in 2019-2020 and 2020-2021, in comparison to those at higher rates, while FS2 exhibited the highest fertilizer use efficiency. When fertilization (CK) was sufficient, the dry matter accumulation decreased by 3.33%- 17.08%, and the harvest index increased by 0.87%-47.40%. FS1 had the highest spike number, which significantly increased by 17.98%, 17.80%, and 9.64% compared with CK during 2018-2019, 2019-2020, and 2020-2021, respectively. In conclusion, a reduction in fertilizer application compared with CK could provide excellent production results. The optimal drip fertigation approach for winter wheat production in the arid regions of northwest China was determined to be the N-P_(2)O_(5)-K_(2)O application rate of 166-80-30 kg/hm^(2) when comprehensively considering the winter wheat yield, soil NH_(4)^(+)-N, and NH_(4)^(+)-N, N use efficiency, P use efficiency, and K use efficiency. This research can provide a scientific basis for the responses of winter wheat production to nutrient uptake of drip-irrigated winter wheat in arid and semi-arid regions.展开更多
It is the need of time that oil palm farmers must perform the spatially planned soil analysis to know about the fertilizer sufficient and deficient zones of land.Colorimetric method is a suitable and fast solution of ...It is the need of time that oil palm farmers must perform the spatially planned soil analysis to know about the fertilizer sufficient and deficient zones of land.Colorimetric method is a suitable and fast solution of soil analysis for NPK determination using the digital soil test kit.NPK determination procedure with a digital soil test kit was undefined for oil palm.Furthermore,the digital soil test kit determines the passage of light through an opaque medium of soil solution with a specified reagent.Therefore,environmental light may interfere leading to wrong results of NPK measurement.Likewise,this equipment was non-incorporable with the controller of any VRT fertilizer applicator.In this research,these issues were addressed and the NPK measurement procedure was defined for oil palm plantation by modifying the‘soil to water’ratio in sample soil solution with an optimum environmental light range of 18-23 W/m^(2).‘Soil to water’ratios were found for nitrogen,phosphorus and potassium as 0.31 to 5.00,1.00 to 5.00 and 4.50 to 5.00,respectively to fit the requirement of NPK for oil palm in the prescribed range of the equipment.Validation study of modified digital soil test kit showed that 91.7%N,89.6%P and 93.8%K results of modified digital soil test kit were matched with analytical laboratory method.Thus,the reliability of NPK results using digital soil test kit was enhanced,making the kit incorporable with the controller of variable rate fertilizer applicator through remote monitoring based data acquisition system.The outcome of this research can be used in the development of an IoT network data fusion for dynamic assessment of the NPK variation in the soil and nutrient management in oil palm plantations.展开更多
基金the Jiangsu Agricultural Science and Technology Innovation Fund(Grant No.CX(23)3029)the Natural Science Foundation of Jiangsu Province(Grant No.BK20210410)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.YDZX2024033)the National Key Project of Research and Development Program(Grant No.2023YFD200100102,2023YFD200100204).
文摘Environmental impacts and economic demands are driving the development of variable rate fertilization(VRF)technology for precision agriculture.Despite the advantages of a simple structure,low cost and high efficiency,uneven fertilizer-spreading uniformity is becoming a key factor restricting the application of centrifugal fertilizer spreaders.Accordingly,the particle application characteristics and variation laws for centrifugal VRF spreaders with multi-pass overlapped spreading needs to be urgently explored,in order to improve their distribution uniformity and working accuracy.In this study,the working performance of a self-developed centrifugal VRF spreader,based on real-time growth information of rice and wheat,was investigated and tested through the test methods of using the collection trays prescribed in ISO 5690 and ASAE S341.2.The coefficient of variation(CV)was calculated by weighing the fertilizer mass in standard pans,in order to evaluate the distribution uniformity of spreading patterns.The results showed that the effective application widths were 21.05,22.58 and 23.67 m for application rates of 225,300 and 375 kg/ha,respectively.The actual fertilizer application rates of multi-pass overlapped spreading were generally higher than the target rates,as well as the particle distribution CVs within the effective spreading widths were 11.51,9.25 and 11.28%for the respective target rates.Field test results for multi-pass overlapped spreading showed that the average difference between the actual and target application was 4.54%,as well as the average particle distribution CV within the operating width was 11.94%,which met the operation requirements of particle transverse distribution for centrifugal fertilizer spreaders.The results and findings of this study provide a theoretical reference for technical innovation and development of centrifugal VRF spreaders and are of great practical and social significance for accelerating their application in implementing precision agriculture.
基金Supported by International Plant Nutrition Institute,China Program~~
文摘[Objective] China is the world＇s largest fertilizer consumer. Fertilizer plays an important role in maintaining China＇s food security. Along with population and economic growth, overuse of fertilizers has caused serious environmental problems, such as soil acidification, decline in soil organic carbon, and agricultural non-point source pollution. This study aimed to analyze the factors influencing farmers＂ decision making on fertilizer use, and provide policy recommendations on ways to affect fertilization. [Method] An econometric model reflecting fertilization of rural households was estimated from a survey distributed to 1 043 households randomly selected from 19 provinces in China. [Result] Results of the study showed that education years of fertilizer decision maker, fertilizer quality, organic fertilizer application, fertilizer price, and agricultural product price had significant effects on the fertilizer application rate at 1% level. Soil nutrient affected the fertilizer application rate at 10% level. [Conclusion] Policies aimed at improving the reasonable use of fertilizer should focus on the regulation of chemical fertilizer price, foundation of the organic-inorganic fertilizer system, soil testing, formulated fertilization, and agricultural extension service.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFD1900805 and Grant No.2018YFD020040608).
文摘Excessive fertilizer application is common in the management of winter wheat (Triticum aestivum L.) in northwest China. However, this practice does not necessarily guarantee higher wheat yield and also causes a waste of resources and environmental pollution. The nitrogen (N), phosphorus (P), and potassium (K) fertilizer application rates need to be optimized to reduce the nitrate residue in the soil while maintaining a high wheat yield. Field experiments were conducted in three consecutive growth seasons (2018-2021) on winter wheat in Northern Xinjiang of China with four reduced fertilization (N-P_(2)O_(5)- K_(2)O) rates (FS1: 166-80-30 kg/hm^(2), FS2: 0-80-30 kg/hm^(2), FS3: 166-0-30 kg/hm^(2), FS4: 166-80-0 kg/hm^(2)) and the local fertilization rate (CK: 240-105-38). The soil nutrients, nutrient uptake content of organ, dry matter accumulation, yield, and fertilization use efficiency were investigated. The results showed increasing NH_(4)^(+)-N concentrations in the soil over the three growing seasons, while NO_(3)^(-)-N concentrations decreased in the later experimental years. High soil NH_(4)^(+)-N concentration and low soil NH_(4)^(+)-N residues were observed in FS3. When the control fertilization (CK) was applied, the grains had a higher proportion of N and P, while the N content in grains was relatively low at the high fertilization rate. When the fertilizer supply was insufficient (FS2, FS3, and FS4), the proportion of vegetative organs to the total biomass was relatively low. Lower fertilization rates resulted in higher N, P, and K use efficiencies in 2019-2020 and 2020-2021, in comparison to those at higher rates, while FS2 exhibited the highest fertilizer use efficiency. When fertilization (CK) was sufficient, the dry matter accumulation decreased by 3.33%- 17.08%, and the harvest index increased by 0.87%-47.40%. FS1 had the highest spike number, which significantly increased by 17.98%, 17.80%, and 9.64% compared with CK during 2018-2019, 2019-2020, and 2020-2021, respectively. In conclusion, a reduction in fertilizer application compared with CK could provide excellent production results. The optimal drip fertigation approach for winter wheat production in the arid regions of northwest China was determined to be the N-P_(2)O_(5)-K_(2)O application rate of 166-80-30 kg/hm^(2) when comprehensively considering the winter wheat yield, soil NH_(4)^(+)-N, and NH_(4)^(+)-N, N use efficiency, P use efficiency, and K use efficiency. This research can provide a scientific basis for the responses of winter wheat production to nutrient uptake of drip-irrigated winter wheat in arid and semi-arid regions.
基金This research was supported by Universiti Putra Malaysia in coordination of United Melaka Bhd.(UMB).
文摘It is the need of time that oil palm farmers must perform the spatially planned soil analysis to know about the fertilizer sufficient and deficient zones of land.Colorimetric method is a suitable and fast solution of soil analysis for NPK determination using the digital soil test kit.NPK determination procedure with a digital soil test kit was undefined for oil palm.Furthermore,the digital soil test kit determines the passage of light through an opaque medium of soil solution with a specified reagent.Therefore,environmental light may interfere leading to wrong results of NPK measurement.Likewise,this equipment was non-incorporable with the controller of any VRT fertilizer applicator.In this research,these issues were addressed and the NPK measurement procedure was defined for oil palm plantation by modifying the‘soil to water’ratio in sample soil solution with an optimum environmental light range of 18-23 W/m^(2).‘Soil to water’ratios were found for nitrogen,phosphorus and potassium as 0.31 to 5.00,1.00 to 5.00 and 4.50 to 5.00,respectively to fit the requirement of NPK for oil palm in the prescribed range of the equipment.Validation study of modified digital soil test kit showed that 91.7%N,89.6%P and 93.8%K results of modified digital soil test kit were matched with analytical laboratory method.Thus,the reliability of NPK results using digital soil test kit was enhanced,making the kit incorporable with the controller of variable rate fertilizer applicator through remote monitoring based data acquisition system.The outcome of this research can be used in the development of an IoT network data fusion for dynamic assessment of the NPK variation in the soil and nutrient management in oil palm plantations.
