Intensive use of N fertilizers in modern agriculture is motivated by the economic value of high grain yields and is generally perceived to sequester soil organic C by increasing the input of crop residues. This perception is at odds with a century of soil organic C data reported herein for the Morrow Plots, the world's oldest experimental site under continuous corn (Zea mays L.). After 40 to 50...

Management of crop residues is an important consideration for reducing soil erosion and increasing soil organic carbon. Current methods of measuring residue cover are inadequate for characterizing the spatial variability of residue cover over large fields. The objectives of this research were to determine the spectral reflectance of crop residues and soils and to assess the limits of discrimina...

the shortage of fresh water and growing competition for clear water makes less water available for agriculture production. the great chalange for the coming decades will be the task of increasing food  production with less water, particularly in countries  with limited water and land resources. therefore, increasing of irrigation efficienciy and decreasing of water losses are important factores...

Many factors affecting irrigation model, including irrigation water volume, crop water requirement, production function of irrigation water, rainfall, soil water balance, water sensitive index in different stages of crop growth, the grain market price, irrigation water price, minimum yield, irrigation cost etc are considered. Then a multi-constraints and non-linear optimization irrigation model...

Appropriate benchmarks for water productivity (WP), defined here as the amount of grain yield produced per unit of water supply, are needed to help identify and diagnose inefficiencies in crop production and water management in irrigated systems. Such analysis is lacking for maize in the Western U.S. Corn Belt where irrigated production represents 58% of total maize output. The objective of thi...

The environmental fate of fumigants methyl isothiocyanate (MITC) and chloropicrin (CP) is of great concern for potential air and groundwater contamination while retaining sufficient concentrations for pest control efficacy. The emission, gas phase distribution, leaching, and persistence of MITC and CP were examined in repacked columns filled with sandy soils under three surface conditions: tarp...

The effects of irrigation with dairy factory wastewater on soil properties were investigated at two sites that had received irrigation for > 60 years. Two adjoining paired sites that had never received DFE were also sampled as well as another seven fields from a wider area around the factory. In comparison with paired sites that had not received effluent, long-term wastewater irrigation resulte...

the present pot experiment was undertaken to investigate the phytoremediation potential of corn and oat in soil. treatments consisted of four cadmium (cd) levels (0, 5, 10 and 20 mg l 1) and three irrigation intervals (1, 3 and 7 days), arranged in the form of a complete randomized design with three replications. corn and oat were harvested after 75 and 90 days, respectively. transpiration rate...

Crop residues have been considered during the past decade as alternate energy sources to supplement dwindling fossil fuel sources and enhance energy independence in the United States. Agricultural scientists have demonstrated the importance of crop residues in reducing soil erosion, enhancing the soil physical environment for plant growth, and as a reserve for major crop nutrients. In eastern N...

This study was carried out to investigate the effect of treated wastewater on soil chemical and physical properties. Field experiment was conducted in Borkhar region in Isfahan province in central Iran with two water treatments of wastewater and groundwater under sprinkler and surface irrigation systems for three crops of sugar beet, corn and sunflower. Soil samples were collected to 120 cm dep...