Tillage practices and nitrogen (N) sources are important factors affecting rice production. Few studies, however, have examined the interactions between tillage practices and N fertilizer sources on NH3 volatilization, nitrogen use efficiency (NUE), and rice grain yield. This study aimed to investigate the effects of N fertilizer sources (no N fertilizer, inorganic N fertilizer, organic N ferti...

The efficient management of nitrogen (N) fertilizer and irrigation is of utmost importance because they are two of the greatest expenses for corn production. This project was conducted to determine if yield and efficiency of fertilizer N in corn could be improved by applying N at later developmental stages through a subsurface drip irrigation (SDI) system. Experiments in 2014 and 2015 compared ...

Nutrient management is central in water footprint analyses as it exerts strong control over crop yield and potentially contributes to pollution of freshwater, the so-called grey water footprint. In the frame of grey water footprint accounting, two methods are suggested, the constant leaching fraction approach (10% of applied fertilizer N) and the N surplus approach. We compared both approaches ...

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...

In this study, nitrogen fertilizer was applied to corn (Zea mays L.) at conventional (excessive) and recommended levels, and the growth response was assessed by measuring plant height and stem perimeter. Corn plant maximum height was observed in recommended rates of N fertilizer treatment, and the height without N fertilizer was the same as that receiving excess N fertilizer. Stem perimeter was...

High N loss and low N use efficiency (NUE), caused by high N fertilizer inputs and inappropriate fertilization patterns, have become important issues in the rice (Oryza sativa L.) growing regions of southern China. Changing current farmer fertilizer practice (FFP, 225 kg ha-1 N as three applications, 40% as basal fertilizer, 30% as tillering fertilizer and 30% as jointing fertilizer) to one-tim...

Rice (Oryza sativa L.) grown on a clay soil in a direct-seeded, delayed-flood system as used in the southern U.S. requires 30 to 60 lb/acre more nitrogen (N) fertilizer to achieve maximal grain yields compared to rice grown on silt loam soils. Seasonal N fertilizer accumulation studies are almost non-existent for rice grown on clay soils. Therefore, a two-year field study was conducted to evalu...

Nitrogen (N) losses negatively impact groundwater quality. Spring wheat genotypes varying in N-fertilizer recovery were studied (by using lysimeters) for their potential to minimize NO3-N leaching during spring and summer, over a three-year period. Additionally, we examined to what extent root growth and NO3-N leaching explain the well-known difference found between apparent and isotopic N reco...

estimation of optimum fertilizer rates is needed because of growing economic and environmental concerns. optimum fertilizer rates can be determined by fitting statistical models to yield data collected from n fertilizer experiments. the main goal of this research was to compare and evaluate quadratic, square root, mitscherlich, rectangular hyperbola, linear plus plateau and quadratic plus plate...

Little information exists on the potential for N fertilizer application to corn ( L.) to affect NO emissions during subsequent unfertilized crops in a rotation. To determine if N fertilizer application to corn affects NO emissions during subsequent crops in rotation, we measured NO emissions for 3 yr (2011-2013) in an Iowa, corn-soybean [ (L.) Merr.] rotation with three N fertilizer rates appli...