Effect Of Different Fertilization And Mulch Cropping Treatments On Movement Of Soil Moisture And Nitrogen

Soil moisture and nutrients are two important factors in agricultural production in dryland areas, which are very closely with crop growth and development. The soil nutrient is closely related to fertilizer and tillage. In this study, both field experiments and laboratory analysis were applied to study the effects of different fertilizer application rates and mulching treatments on migration of soil moisture and nitrogen. The results as followed:1. The temporal and spatial variation of soil moisture were different under the different fertilizations. Temporal-spatial distribution of soil water in the profile was related to precipitation and soil configuration. Soil water content in the upper 120cm changed greatly. Except for phosphorus deficiency treatment (N2P0K2), there were low water areas in soil water distribution graph of different nutrient deficiency treatments. And the value, depth and the arised time of minimum water content had the difference in the different treatments. Their order of appearance were nitrogen deficiency treatment (N0P2K2), no fertilizer (N0P0K0), potassium deficiency treatment (N2P2K0) and conventional treatment (N2P2K2), which was mainly affected by rainfall infiltration, soil evaporation and aboveground water consumption and so on. With the soil depth increasing, the density of contour decreased in the soil profile. The peak area of soil moisture contour density gradually increased. The basic contours density area generally occurred in the late growth of topsoil corn.2. Soil NO3-N existed upward and downward migration change in the soil profile. After the spring maize harvest, the accumulation of NO3--N in 0-200cm soil profile had significantly difference in the different nutrient deficiency treatments. The size of the order was:N2PoK2> N2P2K2> N2P2Ko> N0P2K2> N0P0K0. The order of NO3-N residues in the 0-100cm soil layer was: N2P2K0> N2P0K2> N2P2K2> N0P2K2. Except for CK(N0P2K2), the soil nitrate nitrogen under the 100-200cm soil layer was contrary to the upper NO3--N residues, the order was N2P2K2> N2PoK2> N2P2K0> N0P2K2. For the different fertilization of nitrogen, the soil NO3--N residues were:N360> N240>Ni2o>No after spring corn harvest, and the main distribution was 0-80cm soil depth, which could be used to determine rational nitrogen amount from the residual.3. Various organs of plants had different amount of nitrogen for different fertilization. It also had crucial impact on plants growth, so that there were obvious difference between amount of nitrogen and accumulation of nitrogen. The amount of nitrogen of plants with the different nutrient deficiency treatment in order was:N2PoK2> N2P2K0> N2P2K2> N0P2K2> NoPoKo, but the accumulation of nitrogen in order was:N2P2K2> N2P2Ko> N2PoK2> N0P2K2> NoPoKo. With the increasing of nitrogen for different level of nitrogen fertilization, the amount of nitrogen in the upper of plants were improve gradually.4. Different mulching treatment 0-200cm soil water content changed volatility, characterized by "decrease-increase-decrease-increase" trends. Soil water content of 0-40cm of three different mulching treatments at the jointing stage was increased by 11.69%,16.53% and 16.53% respectively than that in seeding time. The capability of water conservation was plastic film+straw mulching> wide plastic film> narrow plastic film. The soil water content of 40-120cm soil layer changed relatively severely in the entire growth period, and the 120-200cm soil layer changed relatively gentle.5. Surface tillage planting could effectively reduce soil nitrate nitrogen leaching and losses, and residual nitrate nitrogen could be available for the next crop nitrogen nutrition. The study found that accumulation of soil nitrate nitrogen of narrow plastic film and wide plastic film were 67.78% and 62.40% of non-mulching, respectively. Soil NO3--N of narrow plastic film, wide plastic film and double mulching film main remnanted in the maize root system, which main distributed in 0-100cm soil layer depth. In the different mulching treatments, depth of the peak and residual of soil nitrate nitrogen in soil profile were different.