Studies On The Effects Of Tillage System And Tobacco Straw Returned System On The Growth And Development Of Rice

Field experiments were conducted in Hunan agricultural university in 2005. Thispaper studied on the effect of different tillage system, different straw returned systemand different straw returned quantity on the dynamic of tiller number of rice, leaf areaof rice, the dry matter accumulation and distribution of rice, the nutrient absorbingcapacity of rice at different stage, yield and yield components of rice. The mainresults were as follows:1. Not only were the tillering faster, but the tiller amount were larger for minimumtillage treatments than conventional tillage treatments, at early stage, the quantities oftillers of minimum tillage treatments in field were also much higher than that ofconventional tillage treatments. The abilities of tillering for different straw returnedsystem were the deep-returned treatments＞mantle-returnedtreatments＞no-returnedtreatments. The effects of different straw returned amount treatments on the abilitieswere the tillering time delayed with the straw returned amount increasing.2. The leaf area index of minimum tillage treatments were always higher than thatof conventional tillage treatments at three growth stage, the increasing extend were30.2%,11.54%,21.2%, respectively; the results of different returned system showed:the leaf area index of different treatments at maximum tillering stage, booting stageand full heading stage all were deep-returned treatments＞mantle-returned treatments＞no-returned treatments, to the different amount treatments for straw returned, in thewhole, the leaf area index increased with the amount of straw returned increased.3. From the difference of dry matter accumulation for different growth stage, asthe time of rice growth went, not only increased the amount of minimum tillage treatments accumulating, but the speed of it fastened; the trend of dry matter ofaccumulation amount for the straw returned treatments at three different growth stagewas mantle treatments＞deep-returned treatments＞no-returned treatments.4. From the point of the amount of nutrient absorbed by rice, the total amount ofN.P.K for minimum tillage treatments weremuch higher than that of conventionaltillage treatments; the nutrient amount of rice absorbing were straw deep-returnedtreatments was the highest, mantle-returned second, no-returned the third.5. The results of rice yield components showed the spikelets per panicle and seedsetting rate of treatments with minimum tillage system were significantly higher thanthat of conventional tillage system, as well as the final yield; The results of differentstraw returned system showed the effective panicles, spikelets per panicle, seedsetting rate and 1000 grain weight of straw deep-returned treatments weresignificantly higher than that of mantle returned and no-returned treatments. The orderfor rice yield of different returned system was: the total of straw returned＞2/3rds＞1/3rds.