Evaluation of a model recommended for N fertilizer application in irrigated rice

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.

Soil Fertility Properties of Tobacco Growing Area in Jiyuan

Soil fertility properties of the main tobacco growing area in Jiyuan （Shaoyuan,Wangwu,Xiaye and Daiyu） in west Henan Province were analyzed. Results showed that Jiyuan was one of the potential areas which could produce tobacco leaves with high quality. Its main properties of soli fertility were as follows：the content of total nitrogen,alkali-hydrolysable nitrogen,olsen-phosphorus and organic matters were suitable for high-quality tobacco production; especially,all the flue-cured tobacco growing areas in Henan Province were rich in available potassium; besides,the concentrate of water soluble chloride ion was at reasonable level. The problem was that the micro-elements such as Zn-DTPA and available boron content were at a low level in individual areas. Based on this survey,the recommendations for fertilization in Jiyuan such as stabilizing nitrogen rate,increasing phosphorus,stabilizing potassium,and applying boron commonly and supplementing zinc for the deficient soils were put forward.

A GIS-Based Database Management Package for Fertilizer Recommendations in Paddy Fields

Over-use of fertilizer in paddy fields could lead to agro-environmental pollution. Therefore, the Paddy Fertilizer Recommendation System (PFRS) application package was designed to aid in the dissemination of fertilizer recommendations for paddy fields. PFRS utilized geographical information system (GIS) ActiveX Controls, enabling the user to select a location of interest linked to a spatial database of paddy field soil characteristics. The application package also incorporated different soil fertilizer recommendation methods, forming a relational database. The application's structure consisted primarily of building database queries using Standard Query Language (SQL) constructed during run-time, based on user provided spatial parameters of a selected location, the type of soil desired and paddy production criteria. PFRS, which was comprised of five modules including: File, View, Edit, Layer and Fertilizer/Model, provided the user with map-based fertilizer recommendations based on selected soil nutrient P and K map layers as well as N characteristics and land use maps.

Revising Nitrogen Recommendations for Wheat in Response to the Need for Support of Variable-Rate Nitrogen Application

Sampling studies in North Dakota conducted from 1994 to 2003 showed that variable-rate N application could be practically directed with zone soil sampling. Results from variable-rate N studies using zone soil sampling were often less than rewarding due in part to the use of a whole-field predicted yield-based formula for developing the N recommendation in each zone. Nitrogen rate studies on spring wheat and durum were established in 2005 through 2009 with the objective to reexamine N recommendations and construct a new system if necessary. The results of the study and archived wheat N response data showed that the state should be divided into three separate N response regions. Within each region historic yields from low to high productivity were defined. The gross N rate was determined using the return-to-N concept developed in the US corn-belt states but with additional consideration for wheat protein value The gross N rate is then modified by credits for previous crop, soil test N from zone soil sampling, tillage systems, excessive straw from the previous year, relative susceptibility to nitrate leaching or denitrification. Finally, the user is encouraged to use common sense and consider whether particular fields have characteristics that require more or less N fertilizer than suggested by the recommendation formulas.

Sufficiency and Deficiency Indices of Soil Available Zinc for Rice in the Alluvial Soil of the Coastal Yellow Sea

To determine the sufficiency and deficiency indices of soil available Zn by the Agro Services International （ASI） method （ASI-Zn） for Zn fertilizer recommendation in rice production in the alluvial soil of the coastal Yellow Sea, the relationship between relative rice yield and soil available ASI-Zn concentration was analyzed from a ten-field experiment with various soil test classes ranging from low to high fertility in 2005 and 2006, and nine Zn fertilizer application rates （0, 7.5 15, 22.5, 30, 37.5, 45, 52.5 and 60 kg Zn/ha） arranged at random with three replications in each field. There was a significant quadratic relationship between soil available ASI-Zn and rice yield, and a significant linear relationship between soil available ASI-Zn concentration and Zn fertilization rate. For rice variety Wuyujing 3, soil available ASI-Zn was deficient when the value was at lower than 1 mg Zn/L, low at 1 to 2 mg Zn/L, sufficient at 1 to 2 mg Zn/L, excessive at higher than 7.5 mg Zn/L. Thus, Zn fertilizer recommendation could be done according to the sufficiency and deficiency indices of soil ASI-Zn. For most of alluvial soils of the coastal Yellow Sea in the study, the available ASI-Zn was lower than 1 mg Zn/L, and then the optimum application rate of Zn fertilizer was about 20 kg Zn/ha.

The Nutrient Expert decision support system improves nutrient use efficiency and environmental performance of radish in North China

Excessive fertilization has led to nutrient use inefficiency and serious environmental consequences for radish cultivation in North China.The Nutrient Expert(NE)system is a science-based,site-specific fertilization decision support system,but the updated NE system for radish has rarely been evaluated.This study aims to validate the feasibility of NE for radish fertilization management from agronomic,economic,and environmental perspectives.A total of 46 field experiments were conducted over four seasons from April 2018 to November 2019 across the major radish growing regions in North China.The results indicated that NE significantly reduced N,P_(2)O_(5),and K_(2)O application rates by 98,110,and 47 kg ha^(-1) relative to those in the farmers’practice(FP),respectively,and reduced N and P_(2)O_(5) inputs by 48 and 44 kg ha^(-1),respectively,while maintaining the same K_(2)O rate as soil testing(ST).Relative to FP and ST,NE significantly increased radish yield by 2.7 and 2.6 t ha^(-1)(4.2 and 4.0%)and net returns by 837 and 432 USD ha^(-1),respectively.On average,NE significantly improved the agronomic efficiency(AE)of N,P,and K(relative to FP and ST)by 42.4 and 31.0,67.4 kg kg^(-1) and 50.9,and 20.3 and 12.3 kg kg^(-1);enhanced the recovery efficiency(RE)of N,P,and K by 11.4 and 7.0,14.1 and 7.5,and 11.3 and 6.3 percentage points;and increased the partial factor productivity(PFP)of N,P,and K by 162.9 and 96.8,488.0 and 327.3,and 86.9 and 22.4 kg kg^(-1),respectively.Furthermore,NE substantially reduced N and P_(2)O_(5) surpluses by 105.1 and 115.1 kg ha^(-1),respectively,and decreased apparent N loss by 110.8 kg ha^(-1) compared to FP.These results indicated that the NE system is an effective and feasible approach for improving NUE and promoting cleaner radish production in North China.

Optimizing Fertilizer Use by Smallholder Farmers and Economic Returns to Maize in Semi-arid Niger

Maize （Zea mays L.） is an important food crop in Niger, but low and irregular rainfall combined with sandy soils having low fertility level limit productivity. A two-year study was conducted at Institut National de Recherche Agronomique du Niger （INRAN） stations in Tarna/Maradi and Bengou/Gaya in 2014 and 2015 in order to evaluate maize agronomic and economic fertilizer use efficiency. The experimental design was a randomised complete block design （RCBD） with three replications. Results indicate higher effect of fertilizer in 2015 compared to 2014. At low N rates 20 kg N/ha and 40 kg N/ha, application of 20 kg P/ha increased maize grain yield across locations and years. The highest agronomic efficiency of N （AEN） was recorded with 60 kg N/ha in 2015 at Bengou and Tarna with 9.65 kg and 14.05 kg grain yield per kg of applied N, respectively. At Tarna, the low N rates of 20 kg N/ha and 40 kg N/ha recorded important AEN of more than 12 kg yield increases per kg of applied N. The highest rainfall use efficiency （RUE） of 6.13 kg/year/mm was obtained with application of 80 kg/ha N, 0 kg/ha P and 40 kg/ha N, 20 kg/ha P in 2015 at Tarna. Without P, the highest value cost ratio （VCR） value of 4.31 was recorded at Tarna in 2015 with 60 kg/ha N, and the lowest value of 0.08 at Bengou in 2014 with 20 kg/ha N. Based on VCR and RUE derived from this study, the optimal fertilizer recommendation for maize in the semi-arid conditions of Niger could be 40 kg/ha N, 20 kg/ha P and 0 kg/ha K.

Soil Nutrient Detection and Recommendation Using IoT and Fuzzy Logic

Precision agriculture is a modern farming practice that involves the usage of Internet of Things(IoT)to provide an intelligent farm management system.One of the important aspects in agriculture is the analysis of soil nutrients and balancing these inputs are essential for proper crop growth.The crop productivity and the soil fertility can be improved with effective nutrient management and precise application of fertilizers.This can be done by identifying the deficient nutrients with the help of an IoT system.As traditional approach is time consuming,an IoT-enabled system is developed using the colorimetry principle which analyzes the amount of nutrients present in the soil and a fuzzy expert system is designed to recommend the quantity of fertilizers to be added in the soil.A set of 27 IF-THEN rules are framed using the Mamdani inference system by relating the input and output membership functions based on the linguistic variable for fertilizer recommendation.The experiments are conducted using MATLAB for different ranges of Nitrogen(N),Phosphorous(P)and Potassium(K).The NPK data retrieved by the system is sent to the ThingSpeak cloud and displayed on a mobile application that assists the farmers to know the nutrient information of their field.This system delivers the required nutrient information to farmers which results in efficient green farming.

Performance evaluation of IoT-based service system for monitoring nutritional deficiencies in plants

This study aimed to develop and evaluate the performance of a service system platform based on the Internet of Things(IoT)for monitoring nutritional deficiencies in plants and providing fertilizer recommendations.There are two distinct differences between this work and previous ones;namely,this service system platform has been developed based on IoT using a system engineering approach and its performance has been evaluated using dependability.We have successfully developed and integrated a service system platform and chlorophyll meter that is based on IoT.We have also successfully tested the performance of the service system platform using the JMeter software.The dependability value measured from the five tested variables(reliability,availability,integrity,maintainability,and safety)showed a value of 0.97 which represents a very good level of system confidence in not failing to deliver services to users under normal operational conditions.From a future perspective,this platform can be used as an alternative service to monitor nutrient deficiencies in plants and provide fertilization recommendations to increase yields,reduce fertilizer costs,and prevent the use of excessive fertilizers,which can cause environmental pollution.

Alkaline hydrolyzable nitrogen and properties that dictate its distribution in paddy soil profiles

Nitrogen(N) is a key nutrient for rice production, and its bioavailability in paddy soils is strongly coupled to soil organic matter(SOM) cycling. A better understanding of potentially available N forms in soil, such as alkaline hydrolyzable N(AH-N), and their depth distribution will support the development of best management practices to improve the N use efficiency of rice while minimizing adverse environmental effects. Fifteen rice(Oryza sativa L.) fields from Southern Brazil were selected, and stratified soil samples were taken to a depth of 60 cm before crop establishment. Selected soil physical and chemical properties were analyzed to evaluate their relationships with AH-N contents in the soil profile. The AH-N contents below 20 cm varied extensively(increased,reduced, or constant) compared with that above 20 cm. Although clay and clay + silt contents were highly correlated to AH-N for some soils, the major property dictating AH-N distribution by depth was total N(TN), as the correlation between TN and AH-N was mainly by direct effect. The proportion of TN recovered as AH-N across sites and depths presented high amplitude, and thus AH-N was not a constant N pool across depths, indicating that AH-N can be affected by soil management practices even when TN showed no major changes. The distinct distribution of AH-N across soil sampling sites and depths indicates that depths greater than 20 cm should be considered when calibrating the AH-N index for N fertilizer recommendations for flooded rice in Southern Brazil.