Effect Of Changes In Soil Water And Heat On Summer Maize Root Under Subsoiling Seed Condition

In order to study the influence of soil water and heat under subsoiling seed and no-till seed on root growth of Summer Maize,the experiment was carried in Shenzhou experimental station of dry-land farming institute of Hebei Academy of Agricultural and Forestry Sciences on2BMSQFY-4with Zhengdan958of maize from2012to2013.And the paraffin section technology of maize roots was optimized based on the structure character of maize roots.The main results are as follows:1. Effects of different soil tillage managements on soil physical properties were studied. After subsoiling,the layer became looser,and the plow pan was broken. The soil bulk density and soil compaction of the10-30cm layer reduced.As a result,the permeability was improved,and created a good and looser soil environment for maize roots.2. Effects of different soil tillage managements on soil moisture utilization of farmland were studied. As the soil bulk density and soil compaction decreased after subsoiling, seepage rate increased, and the soil moisture content of20-100cm layer was significantly improved,while water consumption was decreased. And this will facilitate the growth of roots to take advantage of soil moisture when the maize encountered high temperature and drought latter in its growth.3. Effects of different soil tillage managements on soil temperature at10cm were srudied.Indicate the magnitude of the diurnal variation of soil temperature after subsoiling increased and daily mean temperature decreased may be due to the changes of soil physical properties and increases of total porosity caused by subsoiling, and then the heat capacity of soil was reduced. Daytime high temperature helps improve root vigor, while reducing root’s respiration and energy consumption in cold night. These effectively promoted the accumulation of photosynthesis products at maize growth stages.4. Identified a more suitable method for the root of maize. After being fixed by F.A.A. liquid, the maize roots were dehydrated in70%,85%alcohol for1hour, and95%alcohol for2hours, and then hyalined in xylene after dewatering twice in100%ethanol for1hour each time. After temperature increased gradually in2days, the pure wax should be replaced for three times with every2hours at58℃before being embedded and sectioned. After being dewaxed with xylene for35minutes, the roots were dyed with sarranine and solid green.5. Effects of coupled water and heat on the micromorphology and surface morphology of maize root were studied. After subsoiling topsoil’s temperature became higher, resulting in higher soil water potential. And soil moisture of20-100cm increased significantly, too. Both of them are conducive to enhance the capacity of maize root to absorption. As a result, the layer of cortex of maize root increased so as to the area of stele and the diameter of vessel. The dry matter accumulation, the root length’s density, the root surface area and length of maize which were subsoiled increased significantly than that of no subsoiling soil.6. Effects of coupled water and heat on the yield components of maize were studied. After subsoiling corn production increased by5.1%in2012,while it increased by8.6%in2013. And water use efficiency increased by3.7%in2012,while it increased by6.0%in2013.what’s more,the subsoiling treatment was significantly higher than the no-tillage treatment on row grains and grain number. Meanwhile, subsoiling tillage in the year of2012also had some impact on the production of2013.