Nitrogen (N) requirements of rice crop are met from both the soil and fertilizers. Because of acute N deficiency in most rice soils, fertilizer N must be applied to meet the crop demand. N fertilizer applied to rice crops is partially lost through different mechanisms, including ammonia volatilization, denitrification, and leaching. These losses may cause environmental problems such as pollutin...

Field experiments evaluated the effects of nematicide and fertility on performance of 'Tifway 419' bermudagrass parasitized by the sting nematode (Belonolaimus longicaudatus). Plot treatments were nontreated or nematicide (1,3-dichloropropene) treated combined with different nitrogen (N) fertilizer levels. Effects of treatments on numbers of B. longicaudatus and turf performance were compared. ...

In this paper we develop a model to estimate nitrogen loading to watersheds and receiving waters, and then apply the model to gain insight about sources, losses, and transport of nitrogen in groundwater moving through a coastal watershed. The model is developed from data of the Waquoit Bay Land Margin Ecosystems Research project (WBLMER), and from syntheses of published information. The WBLMER ...

Wheat is the most widely cultivated food crop in the world, which provides nutrition to most of the world population and is well adapted to a wide range of environmental conditions. Timely and efficient rates of nitrogen (N) application are vital for increasing wheat grain yield and protein content, and maintaining environmental sustainability. The goal of this study was to investigate the effe...

The efficiency with which fertilizer-nitrogen (N) is transferred to grain-N in cereals is usually less than 50% and averages 33% worldwide. Two long-term N fertility experiments were evaluated to examine temporal changes in nitrogen use efficiency (NUE) and their causes. Averaged over 30-yr, non-irrigated winter wheat NUE was 49% at a 22.4 kg N ha 1 yr 1 rate and decreased to 34% at a rate of 1...

Best management practices (BMPs) started in Florida citrus (Citrus spp.) in the 1990s and have evolved to play a major role in production practices today. One of the earliest BMPs in Florida arose from concerns over nitrate-nitrogen concentrations in some surfi cial groundwater aquifers exceeding the 10 mg·L–1 drinking water standard. This occurred in an area of well-drained sandy soils known a...

one of the main problems in crop production in iran is the difference between actual yield and attainable yield which is called yield gap. thus, identifying yield constraints and yield gap are important. to do this, a study was conducted in 95 farms gorgan of in five villages, during two years 2007 and 2008. in this study, all of the information about management operations, soil and crop charac...

The paper presents a detailed understanding of nitrogenous fertilizer use in Indian agriculture and estimation of seasonal nitrogen loosses from rice crop in Indo-Gangetic plain region, the ‘food bowl’ of the Indian sub-continent. An integrated methodology was developed for quantification of different forms of nitrogen losses from rice crop using remote sensing derived inputs, field data of fer...