Saysmosd is a computer program used to predict soil moisture, salinity of groundwater and drainage, depth of groundwater table, and drainage flow in irrigated farmland, using different hydrogeological and aquifer conditions to send different water management options, including groundwater for irrigation, and some crop rotation schedules, where spatial changes are explained by polygonal networks 。

DSSAT is a software application program, which contains dynamic crop growth simulation models of more than 40 crops. DSSAT is supported by a range of utilities and applications, including weather, soil, genetic, crop management and observational experimental data, as well as sample datasets for all crop models. Crop simulation models simulate growth, development and yield as a function of soil plant atmosphere dynamics. DSSAT has been used in many applications, from genetic modeling to farms and precise management, to regional assessment of climate change and its impacts. DSSAT has been used for more than 30 years by researchers, educators, consultants, promoters, growers, private enterprises, policy and decision makers, and many people in more than 150 countries around the world.

Epic is a continuous simulation model used to study the long-term effects of various soil erosion factors on crop production. Epic is a public domain model for studying the impact of soil erosion on crop production in more than 60 countries in Asia, South America and Europe. The model is used to study soil erosion, economic factors, hydrological models, weather effects, nutrition, plant growth dynamics and crop management. The main components of the epic are weather simulation, hydrology, erosion deposition, nutrient cycling, pesticide fate, plant growth, soil temperature, farming, economy and plant environmental control. Epic assessed the impact of soil erosion on productivity and predicted the impact of management decisions on soil, water, nutrient and pesticide movement, as well as their combined effects on soil fertility and managed soil loss, water quality and crop yield.

It is a new process based cotton model to simulate the growth and development of Upland Cotton (Gossypium hirsutum L) with minimal data input during the whole growing season. CPM predicts the final cotton yield for any combination of soil, weather, variety and management behavior.

PHREEQC is a computer software (Parkhurst and appelo, 1999) for the calculation of various low-temperature hydrogeochemical reactions. PHREEQC, based on the ion linked water model, can (1) calculate the species and saturation index of matter formation; (2) simulate geochemical inversion process; (3) calculate batch reaction and one-dimensional migration reaction. In addition, PHREEQC coupled with multi-component solute transport model can generate PHAST, a three-dimensional reaction transport simulator for simulating groundwater flow system. PHREEQC is also useful in the investigation of unpolluted and polluted environment, laboratory, field and regional investigation. PHREEQC can investigate various natural and human influenced environmental geochemical reactions, including acid mine water discharge, radioactive waste isolation, pollutant migration, nutrient enrichment, aquifer natural and artificial restoration, aquifer reserve recovery, drinking water treatment, indoor experiment and regional aquifer system. PHREEQC has two graphical user interfaces available. Phreeqcl is a screen driven interface that provides a descriptive explanation for each data item (Charlton and Parkhurst, 2002). PHREEQC used in windows is a row editing object interface. Its additional input features enable it to generate graphic simulation results (post, 2004).