Effect Of Different Cultivation Patterns On Root Growth And Water Use Of Winter Wheat In Dryland

The low level of soil nutrient and water is the main difficulty for Dry-land farming of Loess Plateau, so improving the yield and WUE of crop is the key issue of sustainable Dry-land farming. In order to provide theory basis and guide for sustainable Dry-land farming,two native winter wheat varieties (Changwu134 and Changhan58) were choosed as materials,the influence of different cultivation patterns (consisting of density, fertilizer and mulching ) on root characterisitics and water use were studied by field experiment. the main results obtained in this study are as follows:1. The shoot population index (biomass,LAI, tiller numbers leaves'Pn of Changhan 58 increased as fertilizer amount increasing,the application of nitrogen during jointing improved shoot dry weight after flowering and biomass during mature stage, so it could get higher yield compared with CK. Basal application of manure and the application of nitrogen during jointing could get higher yield population through increasing harvest index, reduce leaves'senescence rate compared with the treatment with the application of nitrogen during jointing, even its Pn decreased during filling stage.Basal application of manure and the application of nitrogen during jointing increased root amount and water consumption significantly,throughing decreasing surface water consumption ratio while increasing deeper water consumption and ratio which accordance with the root profile.And the yield and WUE also increased as fertilizer amount increasing,the application of nitrogen during jointing improved the yield and WUE,basal application of manure and the application of nitrogen during jointing improved the yield and WUE significantly.2. Single plastic mulch, single manure improved shoot population index (biomass, LAI, tiller numbers) and leaves'Pn,single plastic mulch increased leaves'Pn, LAI, so it could get higher yield, but it improved leaves'senescence rate. Plastic mulch during whole growth stage was more favorable to get higher yield for Changwu 134, while Changhan 58 appeared early senescence more obviously. Single manure consumed more water,at the same time it delayed the leaf senescence ratio during flowering to filling stage,so it was more favorable for biomass accumulation after flowering.After the application of manure,the shoot population index and Pn during jointing of the plastic mulched wheat increased,especially its spikes increased signiciantly,it also kept higher LAI and biomass during filling even its Pn decreased,the rate of Changhan 58's leaves senescence was bigger than Changwu 134,so it got higher yield.Single plastic mulch,single manure or mixed application of plastic mulch and manure increased two winter wheats'root amount obviously or signiciantly,and consumed more water,root amount and water consumption were influenced more by single manure compared with single plastic mulch, they were influenced most by mixed application of plastic mulch and manure. So mixed application of plastic mulch and manure was the most favorable for the amount of root and water consumption.Single plastic mulch,mixed application of plastic mulch and manure increased yield and WUE of winter wheat,single manure could get more yield, but it couldn't get higher WUE. Because single plastic mulch was better at increasing soil temperature,saving water, increasing yield, so it could get higher WUE. And after the application of manure,plastic mulched wheat improved water consumption (3.2-3.6%) weakly,while the yield was increased sharply by (6.5%-20%), so it got the biggest WUE.3. After plastic mulched wheat reduced density,its biomass reduced obviously during the early stage,but the differences became smaller,its tiller numbers of per plant,Pn and LAI increased,and it delayed the leaves'senescence ratio during flowering to filling stage,so it was favorable for biomass accumulation after flowering,there were no obvious differences of the biomass and yield between reduced density and common density. On the contrary,its root amount increased,root weight and area of Changwu 134 increased signiciantly, water consumption was less influenced,it also improved grains per spike and 1000- grain weight, so it could keep higher yield and WUE. The results showed the shoot and root of plastic mulched wheat had strong ability of population adjusting.4. Changwu 134 had higher tillering ability compared with Changhan 58,and the leaves'Pn of Changwu 134 during jointing were higher than Changhan 58, plastic mulching, basal application of manure and plastic mulching, mulch wheat reduced density, Changwu 134 also got higher Pn during booting and filling. Changhan 58 was influenced by basal application of manure and plastic mulching and Single plastic mulch more than Changwu 134; root of mulching wheat Changwu 134 had stronger ability of population adjusting. 20-60 cm's root length and ratio of Changwu 134 were higher than Changhan 58, and the whole amount of its water consumption, water consumption and ratio under 100 cm's soil were also higher. Changhan 58 had higher yield and WUE compared with Changwu 134. Plastic mulching basal application of manure and plastic mulching increased yield and WUE of Changwu 134 more than Changhan 58.