Browsing by Author "Mthandi, J."

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    How much nitrogen would move down? Evaluating the effect of water application regimes on n leaching in the soil
    (Research Journal of Agriculture and Environmental Management, 2015) Mthandi, J.; Salim, B.A; Kahimba, F.C.; Tarimo, A.K.P.R; Lowole, M.W.
    Nitrogen is the nutrient most often deficient for crop production and its use can result in substantial economic return to farmers. However, when N inputs exceed crop needs, excess N may contaminate water. N Management is therefore important to achieve a balance between profitable crop production and environmentally tolerable levels. The aim of this paper is to evaluate the impact of water application regimes on the leaching of nitrogen. The research study was conducted at Nkango Irrigation Scheme in Kasungu district. Maize (SC 407) planted on Julian day of 2012152 and harvested Julian day of 2012250 was used as test crop in the study. The water regimes were full (100%) water requirement regime (FWRR) of maize plant; 60% of FWRR; and 40% of FWRR. The nitrogen application regime used was 92 N kg/ha which was constant.. The EU-Rotate_N model was run to quantify nitrogen leached below 90cm of the soil profile. The study found out that water application regime has a large influence on N leaching. The study concluded that applied water in the soil should not exceed field capacity of the soil and in such way leaching of nitrogen will be minimised.
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    Using EU-rotate_N model to determine effects of nitrogen application dosage on N leaching
    (International Journal of Research in Agricultural Sciences (IJRAS), 2015) Mthandi, J.; Kahimba, F.C.; Tarimo, A.K. P.R.; Salim, B.A.; Lowole, M.W
    Nitrogen losses by leaching only occur when the capacity of the ecosystem to accumulate nitrogen has been saturated (which may take considerable time if the rate of nitrogen input is low). The research study was conducted at Nkango Irrigation Scheme in Kasungu district to determine the impact of nitrogen application regime on N leaching. Maize (SC 407) was a test crop. The planting and harvest were done on Julian day of 2012152 and 2012250 respectively. Water regime was kept constant at 100% of maize full water requirement regime (FWRR) while N application varied from 92 kg N/ha which represents Typical Nitrogen Placement Rate in the area (TNPRA), 125% of TNPRA (115 N kg/ha); 75% of TNPRA (69 N kg/ha); to 50% of TNPRA (46 N kg/ha). The EU-Rotate_N model was used to run the field data. The paper concluded that treatments that received high amount of inorganic N fertilizer lost more nitrogen through N leaching. Plant roots will only absorb nitrogen it requires leaving excess to be leached by water below the active rooting zone. The study also concluded that EU-Rotate_N model to perfectly predict N leaching from irrigated maize production. The study also found out that applying N fertilizers at once increase its susceptibility to leaching and therefore the study recommended that to apply N fertilizer in several small applications during the cropping season.