use of nitrogen fertilizers has contributed much to the remarkable increase in food production that has occurred during the past 50 years. however, environmental and economic challenges due to nitrogen application in agricultural have increased regard to nitrogen use efficiency (nue). studies conducted around the world shows that only half of nitrogen fertilizer inputs is taken up by crops. unf...

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...

In 2004, a study was conducted in the ‘Cutfield’ or Britain Farm at the Cotton Branch Experiment Station with five total N-fertilizer rates (0, 30, 60, 90 and 120 lb N/acre) on ‘FiberMax 960’ (FM 960) cotton (Mozaffari et al., 2005). The experimental design was a randomized complete block design with 5 treatments and 4 replications, resulting in 20 plots. Each plot was approximately 115 ft long...

Application of litter and other organic by-products to agricultural land off site of animal production facilities has created both environmental concerns and agro-economic opportunities, but limited long-term, field-scale data are available to guide management decisions. Thus, the objective of this study was to determine the water quality effects of repeated annual poultry litter application as...

Soil N is a major factor limiting crop production in maize-based agriculture in the tropics. In this study, soil N dynamics and efficiency of N use by maize was investigated in five cropping systems (CSs) over two annual cropping phases. The CSs comprised cereal-legume (CS1, CS2, CS3), cereal-cereal (CS4) and cereal-bare fallow (CS5) rotations with three rates of N fertiliser application to mai...

Phosphorus (P) added to soil from fertilizer or manure application could pose a threat to water quality due to its role in eutrophication of fresh water resources. Incorporating such amendments into the soil is an established best management practice (BMP) for reducing soluble P losses in runoff water, but could also lead to higher erosion. The objective of this study was to test whether incorp...

The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining...

The use of solid dairy manure for sugarbeet production is problematic because beet yield and quality are sensitive to deficiencies or excesses in soil N, and soil N availability from manure varies substantially depending on the year of application. Experimental treatments included combinations of two manure rates (0.33 and 0.97 Mg total N ha−1) and three application times, and nonmanure treatme...