Research On The Soil Fertility Characteristics Of Maize With Full Plastic-film Mulching On Double Ridges And Planting In Catchment Furrows

The essential measures of regulating maize production involve the fertilization,density, cultivation methods. These measures not only affected promotion of maizegrowing, law of moisture migration, absorption and utilization of soil nutrient andchanges of soil fertility, but also controlled the forming of grain yield. The influencesof interaction effects of density and fertilizer on soil moisture transporting, soilnutrient, soil enzyme activity and maize yield in maize with full plastic-film mulchingon double ridges and planting in catchment furrows being made clear has importanttheoretical signifiance and practical value in improving the cultivation techniques offull plastic-film mulching on double ridges and planting in catchment furrows andrealizing high yield and scientific cultivation of maize in dry-land. The change of soilmoisture, soil nutrients, soil enzyme activity and maize yield were researched throughfield trials in Dingxi arid meteorology and ecological environment experimentalstation from2011to2012. Hoping to provid scientific basis for high yield andefficiency of maize with full plastic-film mulching on double ridges and planting incatchment furrows. Main results are as follows:1. The changing trends of soil organic matter and alkaline hydrolysis nitrogencontent of all treatments in the whole growth period of two planting densities and twolayers was consistent. The soil organic matter, total phosphorus and alkalinehydrolysis nitrogen content of all treatments peaked at seeding period, the contentcontinues to reduce along with the maize period propulsion. The content of totalnitrogen and available phosphorus consistently followed an increasing trend duringthe earlier part of the growing period. However, total nitrogen and availablephosphorus content declined during the latter part of the growing period. Comparedwith others soil nutrient content, soil total nitrogen and total phosphorus content wererelatively stable and the change rate were not great in the whole growth period.Planting density had positively significant（p<0.05）or extremely significant(p<0.01)impact on soil total nitrogen, total phosphorus, alkaline hydrolysis nitrogen andavailable phosphorus content of the soil layers of0to20cm and20to40cm. Soil totalnitrogen, total phosphorus, alkaline hydrolysis nitrogen and available phosphoruscontent of dispose NP1(N:0kg·hm-2;P:0kg·hm-2) was the lowest of the soil layers of0 to20cm and20to40cm in the whole growth period. Each fertilizer applicationtreatment all can improve the soil organic matter, total phosphorus and alkalinehydrolysis nitrogen content in different level, and the effect of disposeNP4(N:180kg·hm-2;P:144kg·hm-2) and NP5(N:210kg·hm-2;P:168kg·hm-2) were thebest. Dispose D2NP5improve soil nutrient content were most effectively of soillayers of0to20cm and20to40cm in the whole growth period under fertilizer anddensity interaction conditions, There was no obvious effects on soil total nitrogen andtotal phosphorus content of fertilizer and density interaction.2. The activity of soil urease, phosphatase, invertase and catalase consistentlyfollowed a rapid increasing trend during the earlier part of the growing period. Theactivity of urease，invertase and catalase peaked at jointing stage, but the highestvalue of phosphatase activity at tasselling stage. However, various soil enzymes’activity declined during the latter part of the growing period. Planting density hadpositively significant（p<0.05）or extremely significant(p<0.01)impact on soil urease,phosphatase and invertase. The effect was different at different growth periods andsoil layers. The activity of soil urease, phosphatase, invertase and catalase of disposeNP1(N:0kg·hm-2;P:0kg·hm-2) was the lowest of the soil layers of0to20cm and20to40cm in the whole growth period. Each fertilizer application treatment all canimprove the activity of soil urease, phosphatase, invertase and catalase in differentlevel, and the effect of dispose NP4(N:180kg·hm-2;P:144kg·hm-2) and NP5(N:210kg·hm-2;P:168kg·hm-2) were the best, and there existed positively significant（p<0.05）correlation with dispose NP1(N:0kg·hm-2;P:0kg·hm-2) in the wholegrowth period. Fertilizer and density interaction had obvious effects on the activity ofsoil urease, phosphatase, invertase and catalase. Dispose D2NP5improve soil enzymeactivity were most effectively of soil layers of0to20cm and20to40cm in the wholegrowth period under fertilizer and density interaction conditions.3. The content of soil moisture changing trends of all treatments in the wholegrowth period of two planting densities was the same. It is shown as: Wi-th thedeepening of soil layer, the soil moisture content of each treatment was reducedcontinuously. The most effectively improve soil moisture content of di-spose NP6(N:240kg·hm-2;P:192kg·hm-2) was the planting densities of4.5×104plant·hm-2(D1), and the effect was most obvious. Soil moisture content increas-ed with increasingfertilizer in the soil layer of0to20cm of heading period and filling period in highplanting density, which played a significant role in maintaining soil moisture. Theaverage soil moisture content of6.75×104plan-t·hm-2(D2) planting density waslower than4.5×104plant·hm-2(D1) in the wh-olegrowth period.4.There existed positively significant（p<0.05）or extremely significant(p<0.01)correlation between barren tip length, ear length, number of grains per row andtheoretical grain yield of different densities; There existed positively significant effectbetween ear length, number of rows per ear, number of grains per row,100-grainweigth and theoretical grain yield of different fertilization treatments; There existedpositively significant effect between barren tip length, ear length, ear diameter,number of grains per row,100-grain weigth and theoretical grain yield of fertilizerand density interaction conditions. Water consumption of4.5×104plant·hm-2(D1)planting density was lower than6.75×104plant·hm-2(D2), the actual grain yield andWUE of D1planting density was lower than D2planting density. In the arid orsemiarid areas of West China, the optimal application rate required by maize with fullplastic-film mulching on double ridges and planting in catchment furrows was210kgN hm-2for N fertilizer and168kg P2O5hm-2for P fertilizer when plant density wasconformed to be6.75×104plant hm-2.