EFFECT OF SOIL, LAND USE, AMC AND SLOPE ON NUTRITION LOSS OF SOIL

Abstract

The experimental field located in Toda Kalyanpur, Roorkee, dist. 1-laridwar, Uttarakhand, India, which is the study area, lies in alluvial plain of River Ganga and is a fertile agricultural field. Primarily, three main plots having different slopes of 5%, 3% and 1% were prepared in this experimental field. Each plot was sub-divided into four sub-plots of 22mx5m size having different land uses such as: sugarcane, maize, black gram and fallow land. The types of soil of the field was determined by conducting double ring infiltrometer and were found to fall under respective hydrologic soil groups IA', E3' and AC', describing the soil textures as sandy soil, sandy loam and clayey loam respectively. The hydro-meteorological data for 6 natural rainfall-runoff events were observed during monsoon period (June-August, 2013). However, for the total Nitrogen (N) losses, data of 2 events only were available for plots having slopes of 3% and 1%. The average runoff values from the plots of different slopes were of the order of 19.15mm for 1%, 18.66mm for 3%, and 18.22mm for (5%). The reversal of the runoff values with plot gradient is attributed the effect of antecedent moisture condition (AMC). The average runoff coefficient was observed the highest for sugarcane (0.45) and lowest for fallow land (0.14) at 1% slope. The corresponding sediment yield (total of 6 events) varied as: 1.37 t/ha for 1%, 1.28 t/ha for 3% and 1.14 t/ha for 5% slope. Similar to the above, the total nutrient losses from these slopes varied as: 1.22 kg N/ha for 3%, 1.03 kg N/ha for 1%; 10.26 kg P/ha for 5%, 5.05 kg P/ha for 3%. 4.31 kg P/ha for 1%, and 7.67 kg K/ha for 3%, 7.11 kg K/ha for 1% and 6.09 kg K/ha for 5% slope. With respect to the soil type, the total nutrients losses varied as: clayey soil (1.30 kg N/ha) > sandy loam (I .11 kg N/ha) > sandy soil (0.95 kg N/ha); clayey soil (7.27 kg P/ha)> sandy loam (6.38 kg P/ha)> sandy soil (3.59 kg P/ha) and clayey soil (7.53 kg K/ha) > sandy loam (7.27 kg K/ha) > sandy soil (6.67 kg K/ha). Again, with respect to land uses, the total nutrients losses varied as: sugarcane (1.52 kg N/ha)> maize (1.26 kg N/ha)> black gram (1.21 kg N/ha)> fallow land (0.47 kg N/ha); sugarcane (14.72 kg P/ha)> maize (7.80 kg P/ha)> black gram (2.86 kg P/ha) > fallow land (0.78 kg P/ha) and black gram (9.42 kg K/ha) > maize (6.85 kg K/ha) > sugarcane (5.85 kg K/ha) > fallow land (5.71 kg K/ha). Thus, the results exhibit a significant effect of runoff, sediment yield, soil, and land use on total nutrients losses.