Loss of nutrients from meadow-brown soils during irrigation of apple trees in the conditions of the dry subtropics of Azerbaijan

Abstract

   The article presents the results of studies on the effect of water consumption, depending on the length (96, 144 and 192) meters of irrigation furrow with a slope of relief tg = 0.021 on the leaching of nitrogen, phosphorus and humus from irrigated soils of the dry subtropics of Azerbaijan under apple trees. Under conditions of leaching of nutrients, the effect of mineral and organic fertilizer systems on apple yields has also been studied. With a 96-meter furrow and a water consumption of 0.2 l/sec, the content of leached nutrients (N, P) and gross humus with soil was 0.01 % nitrogen and phosphorus, 0.02 % gross humus. Increase in water consumption from 0.2 l/sec. up to 0.4 l/sec. It has a negative effect on the leaching of humus, nitrogen and phosphorus from the soil. With a water consumption of 0.4 l/sec, these indicators increased markedly by 0.01 % for humus, nitrogen and phosphorus. Along the length of the irrigation furrow in both water consumption rates, the leaching of nutrients and humus from the soil increases. It was found that with an increase in the length of the furrow to 192 meters at a water consumption of 0.4 l/sec, the leaching was greater than the 96-meter furrow in humus by 0.22 %, nitrogen by 0.07 % and phosphorus by 0.04 %. The use of an organomineral fertilizer system (Background+ N120P120K90) had a positive effect on the yield of apple trees. Thus, in the non-maneuverable version on a 94–meter furrow, the yield of the apple tree was 274.2 c/ha - when the furrow was lengthened to 192 m, the yield gradually decreased due to the high content of leached nutrients and humus (268.5 c/ha). When using N120P120K90 + 10 t/ha of manure, 278.4 c/ha yield was established at 96 m furrow and 0.2 l/sec of water consumption. Whereas, when the furrow was lengthened to 192 m at the same rate of fertilizers and water consumption, the yield decreased to 278.2 c/ha, that is, furrow lengthening was ineffective at slopes tg = 0.021. It was found that at high slopes, the shorter the furrow, the less nutrients are washed out.