Preliminary Study On High Yield Formation Of Rice For Ridge-cultivation In Southern Of China

Yield characteristics of rice ridge-cultivation was studied with three cultivar (9You418,Wujing15,Huaidao 9) in Jiangsu province in the southern China during 2006-2007. The key cultivation techniques included cultivars, densities, seedling-raising methods , nitrogen application and so on were analysed. The main results were as follows:1. The yield and its components of ridge-cultivation were studied systemically. The result clearly showed that the ridge-cultivation had a significant effect increasing the yield (23.3kg/mu)in the rice of the southern China. Of all the yield components, the effective panicles ,1000-grain weight and grain-filling rate increased while the spikelets per panicle decreased. The effective panicle increased mostly, followed the grain-filling rate , 1000-grain weight was the lest.2. The rice cultivar high yield effect on rice ridge-cultivation is strain of rice, Wujing 15 got the highest yield, 51.5 kg / mu (8.3%)higher than Huaidao 9 .Wujing 15 is suitable for rice ridge-cultivation; the ridge-cultivation used the method raising the seedling with plastic tray has advatages in panicles, spikelets per panicle , 1000-grain weight and grain-filling rate than dry rice seedling method , the former produced 38.2 kg / mu than the later, increase production 38.2 kg / mu; the nitrogen application of the ridge-cultivation was that base-tiller fertilizer : Ear fertilizer = 5:5, it has a great advantages than the treatment base-tiller fertilizer : Ear fertilizer = 7:3 in spikelets per panicle , 1000-grain weight and grain-filling rate, the former produced 24.5 kg / mu than the later.The ridge-cultivation got the high yield at the density 12,000hole/mu, 2-3plants/hole.3. This article expounded the mechanism getting high yield from the root quantity, the root vigor, LAI, the dynamic changes of the stems and tillers and dry matter accumulation and so on. the rice ridge-cultivation had significant positive effects in improving the total number of roots and the root vigor, the dry matter weight of the maximum root increased 48.4%, it also increased the depth of root system; the dynamic changes of the stems and tillers and the LAI of the Rice ridge-cultivation raised quickly at the earlier growing period, maintaining steady at the mid-term stages, declining slowly at the later period .which helps prolonging the time of photosynthesis. The accumulation of the dry matter raised slowly at the earlier growing period, increased rapidly at the later period,and kept a higher dry matter accumulation at the maturity.4. From the plant type, population structure, spatial distribution of material and so on, this article expounded that the rice ridge-cultivation can improve the conditions of receiving sunlight, the three top leaves in the stem have a good light .the leaf basic angle and the leaf drooping angle become small, the plant became dwarf. The base internode became shorter, the column under the ear became longer ,the base internode became stronger, the center of gravity moves downward . the vertical distribution of the organ hastens reasonably .Which can accommodating a large ear sink and had a strong ability to resistant the lodging. Mechanism getting high yield from the root quantity, the root vigor, LAI, the dynamic changes of the stems and tillers and dry matter accumulation and so on..In 2 years experiment, the rice ridge-cultivation did not appear lodging, while the normal seedling-raising method appear the lodging of varying degrees.5. In sum, the ridge-cultivation can alleviate the lodging as well as the problems the rice population oversized in the middle and later growing period , the earlier senescence of the root, the grain sink can not be effectively filled and so on happened in the rice of the southern China in the certain extent and increased the yield significantly. Therefore, the ridge-cultivation will be a new way to get the high yield of rice of the southern China hopefully.