modeling of crop growth plays an important role in evaluation of drought impacts on rainfed yield, choosing an optimum sowing date, and managerial decision-makings. aquacrop model is a new crop model that developed by food and agriculture organization (fao), that is a model for simulation of crop yield based on “yield response to water“ with meteorological, crop, soli and management practices d...

this study investigated the efficiency of wheat farms in sistan province. the data consisted of 50 samples from crop producers in the sistan region. using the simple sampling method, the data was collected by completing the questionnaires. to evaluate the farm efficiencies, the two approaches of the “data envelopment analysis” and the “optimization model including parameters to control for the ...

A water simulation model (WaSim) to simulate the growth and development of Amaranthus cruentus as well as the components of water balance for a typical sandy-clay-loam soil of Akure has been described. Dry season experiments were carried between January and March of 2005 and 2006. Amaranthus seeds were established on the field and three irrigation water managements were imposed on the crop to d...

Traditional decision support systems based on crop simulation models are normally site-specific. In policy formulation, however, spatial variability of crop production often need to be evaluated due to different soil conditions, weather conditions and agricultural practices within a target-region. To address the spatial variability, a spatial model “Spatial EPIC” was developed based on a crop s...

The adaptive responses of crop genotypes and patterns of genotype x location (G x L) interaction are important to crop improvement as they are the basis for selection for specific adaptation and for elucidation of the causes of G x L interaction. Their legitimate assessment, however, requires yield data for the test genotypes for a large number of sites and over multiple years. Such data are se...

abstract rice is most important agricultural crop of guilan province sensibility to salinity and alkalinity of water and soil. in recent years, using of toxicants and fertilizers in farmlands, constructing several dams upstream, entering agricultural, homemade and industrial sewage in to a river, and drought have decreased gradually discharge of river and increased salinity of sefidrud river as...

precise application of the n fertilizer rate is critical to achieve maximum yield. in major regions, empirical methods were used for determining n fertilizer requirement. these methods cannot take into account variation in management and environmental conditions on determining fertilizer requirement. crop simulation models can provide an alternative means of determining the optimum crop n requi...

abstarct precise knowledge of all components of water balance is essential to optimize water use in irrigated agriculture. however, water balance components are difficult to measure in required time intervals because their measuring is time consuming and costly. unsaturated zone simulator models are useful tools for predicting the effects of agricultural management on crop water use and can be ...

Crop model simulates growth and yield of crop in field scale and can be used to provide useful field information for farmers, such as irrigation application dates and amount, fertilizer application dates and amount, the choose of crop variety. Researchers have used crop models for many years, but they have had limited success in packaging these complex models in a framework that make them easy ...