Effect Of Different Tillage And Straw Coverage And Irrigation Modes On Rice Productivity And Soil Physical And Chemical Properties

F you 498, a hybrid rice with heavy panicle was used to investigate the performance of grain yield, transportation of dry matters, moisture content of rice plants, Pn, SPAD values of top three rice leaves, roots, root activity and the affact of soil nutrient absorption use, under different ditch-irrigation managements, which included the traditional shallow irrigation, infiltration irrigation, alternation irrigation under conservation tillage models. The main results are as follows:As for F you 498 with heavy panicle under conservation tillage, insufficient source has always been the limit factor to increase grain yield. In this research:1. No-till and plough, the later yield was higher, dued to the higher of enough effective panicle, spikelets per panicle, seed-setting,1000-grain and the transportation of dry matters, Pn was higher under no-till, and no-till on collaborative alternation irrigation treatment can effectively alleviate the Pn and the aging speed of root activity, laid the foundation for achieving high yield.2. Between no-till covered straw than no-till uncovered straw yield was higher, it is decided by more spikelets per panicle. Ditch-irrigation under no-till, covered with straw or without effective panicle were insufficient, resulted in yield did not increase substantially. The transportation of dry matters, moisture content of rice plants, after full panicle SPAD values of top three rice leaves, root length, root surface area, root volume, root activity were higher under no-till covered straw, so straw mulching and yield significantly positive correlation. Meanwhile straw mulching on collaborative alternation irrigation treatment can effectively alleviate the SPAD values of top three rice leaves and the aging speed of root activity, laid the foundation for achieving high yield.3. But seed-setting rate and 1000-grain both no-till and plough or no-till covered and no-till uncovered straw were quite high, through which to boost photosynthesis of leaves was difficult. Hence, increasing tillers to ensure enough effective panicle and spikelets per panicle, which will boost source and sink together is the ultimate way to solve the contradiction and increase grain yield significantly. The yield and its components were high under alternation irrigation, especially its under straw coverage was more.4.0-10cm soil bulk density gradually decrease in tillering stage to full panicle,but increased slightly after full panicle, showed that the surface soil bulk density reduced gradually on rice roots the influence of such factors under no-till and ploughing conditions.0-15cm soil bulk density gradually increasing in rice fertility period, the no-till covered straw soil bulk density slightly higher than uncovered treatment and infiltrating irrigation density significantly increased under no-till straw coverage.5. Conservation tillage and irrigation management on soil physical and chemical properties; (1) under no-till and plough conditions,0-10cm and 10-20cm soil total nitrogen and effective nitrogen content no-till higher than plough,20-30cm soil total nitrogen no-till below plough, effective nitrogen no-till higher than plough before full panicle, after full panicle was Opposited.0-10cm,10-20cm and 20-30cm soil total phosphorus and effective phosphorus were no-till below plough,0-10cm total potassium and effective potassium content no-till below plough,10-20cm total potassium and effective potassium was higher than plough before full panicle, after full panicle was opposite,20-30cm total potassium and effective potassium were no-till higher. Infiltration irrigation and dry-wet alternate irrigation had better influence on soil total nitrogen and available nitrogen and total phosphous and effective phosphorus content, and the highest content of alternate irrigation under the plough, total potassium and effective potassium were significant difference on water management, but no obvious difference on irrigation methods.(2) The total nitrogen, effective nitrogen, organic matter to the surface soil enrichment under no-till straw. Among them shallow irrigation contributed to total nitrogen (0-10m), effective nitrogen, organic matter content increased; alternate irrigation and infiltrating irrigation was helpful to increasing of total nitrogen content of 10-20cm and was helpful for rice to the absorption of nitrogen. On the other hand, the content of soil effective phosphorus and available potassium gradually reduced in the reproductive period of rice, and 0-10m of soil effective phosphorus and available potassium content decreased covered less than uncovered straw, but 10-20cm soil layer was opposite. Then straw mulching compensate the nutrients in the surface soil, reduced the decline of phosphorus and potassium. Yet irrigation methods impact on the content of soil effective phosphorus and potassium did not reach significant difference levels. Other compartments face middle row of soil fertility and the edge row was not obvious, edge line rice yield was significantly higher than the middle line that was not close relationship.6. Regardless of no-till and plough or straw coverage, rice yield were processed with alternate irrigation was highest and the straw coverage was better. Compared with the traditional shallow irrigation and infiltration irrigation, alternation irrigation would help easing the aging speed of the Pn and the SPAD values of after full panicle and root activity, and improved the root length, root surface area and root volume, but the soil nitrogen, phosphorus and potassium content was also no significant difference. So alternate irrigation combined with straw coverage was the best way of cultivation.