BACKGROUND AND AIMS Numerous estimates have been made of the concentrations of N and P required for good growth of crop species but they have not been defined by any unifying model. The aim of the present study was to develop such a model for the dependence of the N : P ratio on crop mass, to test its validity and to use it to identify elements of similarity between different crop species and w...

Crop evaportranspiration was studied with measured data of Kongque river irrigation district in Xinjiang Province based on application of BP neural networks, a sensitivity analysis about crop evaportranspiration was conducted according to each input factor by using default factor method, and the grey relational analysis method was applied to certify the results.The results showed that the artif...

present limitations on available water resources especially for use in agriculture sector, shows that more attention to irrigation water management is inevitable. deficit irrigation is a practice to improve use of unit volume of water. in this research, efficacy of cropwat 8.0 model was evaluated against field data under deficit irrigation management on soybean in karaj. in 2008 and 2009 agrono...

the greatest limitations to agricultural development and production in iran are scarcity of water resources, ineffective irrigation scheduling and wasteful water usage. avenues discussed for optimum water use include improving water productivity by improving irrigation scheduling, farm water management and water profitability. the present study evaluated current water use and ways to improve wi...

The approach of using multispectral remote sensing (RS) to estimate soil available nutrients (SANs) has been recently developed and shows promising results. This method overcomes the limitations of commonly used methods by building a statistical model that connects RS-based crop growth and nutrient content. However, the stability and accuracy of this model require improvement. In this article, ...

This study investigated the scope and constraints for integrated use of mechanistic crop growth simulation models and earth observation techniques. Integration of highquality crop growth models and information derived from earth observations can contribute to improved use of resources, reduced crop production risks, reduced environmental degradation, and increased farm income. In the past, both...

We investigate the ability of three different crop models of varying complexity for capturing El Niño–Southern Oscillation-based climate variability impacts on the U.S. Corn Belt (1981–2010). Results indicate that crop models, irrespective of their complexity, are able to capture the impacts of climate variability on yield. Multiple-model ensemble analysis provides best results. There was no si...