Effect Of No-tillage On Soil Water, Growth And Water Use Of Maize In Semi-arid Area Of Northern Shanxi Province

Considering the technical problems facing desertification control in northern Shan xi province, wecarried out an experimental research in Shen xi Irrigation Experiment Station of Hun Yuan county, Shanxi province form 2004 to 2006, using experimental methods which integrate field plot experiment withopen country investigation to study the following three cultivation ways in the dryland as conventionaltillage (C₀), non-tillage with stubble (C₁), non-tillage with straw mulch (C₂). Based on our long-termobservation of the soil temperature, soil moisture, and maize development,we studied the soil water-heatconditions when different cultivation patterns were used and the influence of different cultivation wayson corn growth and rule of water consumption, and we also compared the production and ecologicalbenefit of different tillages .The experimental results showed that:First, compared with the conventional tillage, non-tillage with straw mulch has reduced the soiltemperature remarkably in the early stage and minutely in the later stage. Compared with theconventional tillage, non-tillage with stubble slightly reduces soil temperature. As for the changingtendency of daily soil temperature under different cultivation types, they all shows "single peak". Thedifference is unremarkable between no-tillage with stubble and conventional tillage. However, comparedwith conventional tillage, non-tillage with straw mulch increases soil minimum temperature, decreasessoil maximum temperature, and guarantees relatively low daily average temperature and small dailyswing.Secondly, according to our observation from 2004 to 2006, soil moisture varies with the seasonalchange of rainfall and evaporation, and the most arid period of soil is in February in every kind of tillagemethod. As for the anual change of soil moisture, there were higher content of soil overall moisturebecause of relative more rainfall in 2004 and in 2005, and the soil were dry to an much more extent in2006 owing to less rain in that year.Considering the difference of the three cultivation methods, compared with conventional tillage,non-tillage with straw mulch decreases soil temperature, breaks the water exchange between soil and airand significantly increases soil moisture content, particularly at the layer above 100cm and below 160cm.In the early stage, the difference was little, which became bigger with the growth of corn in 2004 andmuch bigger in 2005 and 2006. Compared with that of conventional tillage, in non-tillage with stubble,water content increases in the upper layer of soil, but decreases at medium layer, and generally keepsinvariable at the depth from 0cm to 280cm.Thirdly, different tillage ways changes the soil water and thermal conditions, and accordingly hasdifferent influence on the growth of corn. Non-tillage with straw mulch leads to a slow and poorgermination of corn seed, weak seedling growth, lag of growth period, inadequateness of plant height,weakness of photosynthesis and transpiration, etc. In the middle and latter stage, soil temperature is no longer a limiting factor, and soil moisture playsa key role in corn growth and development. So corns grown by the way of non-tillage with straw mulch,with better plant-height and more efficiency of photosynthesis and transpiration, grows better than thosegrown by conventional tillage. As for the total yield, non-tillage with straw mulch, due to increase of soilmoisture content, boosts the weight of per hundred grains, making ears robust, and baldness short.Therefore, the seed yield and dry matter aboveground is increased significantly and water use efficiencyis enhanced sharply.