Study On Cultural Approach Of Super-high Yielding Rice

The experiments were conducted in the farm of YangZhou University during 2005-2006, with WuJing 15 and ChangYou 1 hao. QianCu, PingHeng and YouZhong ways were designed from hills per-666.7m2 and N fertilizer strategy, and general high-yield cultivated way was CK. Yielding component, dry matters production and rule of N absorbing and using were studied in order to reveal the rule of super-high yielding and cultivated ways of super-high rice which could give the theoretical reference for super-high yielding cultivation. The results as follows:1,Different cultivated ways had great effect on the yielding under super-high yielding cultivation. The sequence of grain yielding was YouZhong>PingHeng>QianCu > ChangGui. YouZhong achieved super-high yielding (WuJing15 was 846.0kg/666.7m2; ChangYou1hao was800.7kg/666.7m2).High population spikelets and normal seed setting were the major reasons of YouZhong super-high yield. QianCu and ChangGui could not achieve super-high yielding because their population spikelets was not enough. YouZhong had enough panicles and grains per-panicle, but QianCu and ChangGui's grain per-panicle was less significantly than YouZhong.So, breeding big panicle based enough number of panicle was the major way to achieve super-high yielding.2,The LAI of super-high yielding rice increased quickly in prophase, which was about 4.0 in elongation stage. The increased number of LAI was large and the max LAI appeared in booting stage which was about 8.0. The rate of effective and high effective LA was high. The former was 92%, the later was 73%. The decrease of LAI was slowly after heading stage. LAI was about 3.5 in mature stage. The LAI of QianCu and ChangGui increased excessively in prophase, which leaded the rate of effective and high effective LA lower. The LAI trend of PingHeng was as like as YouZhong.3,YouZhong had small number of seedling in transplanting stage, which achieved enough panicles in N-n. The peak of tillers was 1.3-1.4 more than panicles in mature stage, and anticipative panicles appeared in heading stage. Population tillers of QianCu and ChangGui increased quickly, and tillers peak appeared early, which was 1.5 more than anticipative panicles. At last, their grains per-panicle was less. Population tillers of PingHeng decreased more quickly than YouZhong after tillers peak. At last, panicles and grains per-panicle of PingHeng were less than YouZhong.4,Different cultivated ways had great effect on the production of population dry matters. The total dry matters of YouZhong was max, and PingHeng was next. QianCu and ChangGui were significantly less than YouZhong and PingHeng. YouZhong's dry matters accumulation concentrated on middle and later stage, but QianCu and ChangGui were the same in prophase, middle or later stage. So, decreasing dry matters in prophase probably and increasing dry matters in middle or later stage could achieve super-high yielding.5,Different ways had great effect on the rule of adsorbing Nitrogen. The total N of population, the rate of N in mature stage, N use efficiency and productive efficiency of YouZhong were max among four cultivated ways. The N ratio of different phase on YouZhong was 25% in foemerstage , 50% in middle stage, 25% in later stage. The diversity between QianCu, ChangGui and YouZhong was great. The former, middle and later were 40%, 30% and 30%. So, properly increasing the ratio of N fertilizer in middle and later stage could effectively enhance yielding and N use efficiency. 6,YouZhong could achieve super-high yielding efficiently, though studying on yield content, leaf and tiller trends, dry matters accumulation and N absorbing and using under different cultivated ways. It made population achieve anticipative panicles in N-n stage, trough probable numbers of seedling in transplanting stage. It made tiller peak 1.3-1.4 more than anticipative panicles, though stopping giving water in achieving 80% anticipative panicles. It used panicle fertilizer in dao4 and dao3 leaf in order to achieve strong tillers and big panicles. It enhanced population in later stage in order to achieve high grain fertility depending on strong tillers, big panicles and high effective leaves in middle stage.