Effect of different mulching measures on nitrate nitrogen leaching in spring maize planting system in south of Loess Plateau

Abstract

Field experiment was conducted in the southern gully region of the Loess Plateau to study the effects of different mulching measures on spring maize yield and nitrate leaching in dryland under the traditional tillage conditions, so as to provide a scientific basis for spring maize planting and environmental protection in this area. The four treatments included non-mulching (CK), plastic film-mulching (PM1), plastic film-mulching in fallow (PM2) and straw-mulching (JM). After 13 years of continuous application, the yield of spring maize, the nitrogen uptake by plants and the nitrate nitrogen content at the harvest stage were measured. The results showed that the soil moisture content and water storage capacity of three kinds of soil mulching treatments were all higher than those of non-mulching ones. Soil water storage in the range of 0 ∼ 300 cm of JM, PM1 and PM2 increased by 11.8%, 10.6% and 8.8% respectively compared with CK. Compared with CK, the mulching treatments significantly increased the aboveground biomass and grain yield of spring maize. The yield enhancement effect of PM1 was the most significant, with a yield of 11,314.42 kg / ha and an increase of 26.72%. In addition to the JM treatment, the accumulation of soil nitrate nitrogen in the range of 0 ∼ 300 cm of PM1 and PM2 was less than that of CK, but the increase of nitrate nitrogen of 80.20% of JM treatment was in the range of 0 ∼100 cm. Therefore, in the rain-fed agriculture in the south of Loess Plateau, mulching cultivation can effectively increase the soil moisture content and water storage, improve crop growth. The yield enhancement effect of plastic mulching-film was the best. PM1, PM2 could significantly reduce the content and accumulation of nitrate nitrogen in soil profile, and the three mulching measures could slow the deep leaching of soil nitrate nitrogen to a certain extent.