Effect Of SRI On Eco-Physiological, Grain Yield And Grain Quality Of Rice

Rice eco-physiological characteristics, population development, grain quality changes and representation of yield, under SRI ( system of rice intensification ) condition were studied by different planting density with hybrid rice Xieyou 527. The main results were as follow:( 1 ) SRI obviously promoted the dry weight of root, especially of root that distributed within 0-12cm of soil layer ( from the surface of soil ), and reduced total soluble sugar content of root, enhanced root activity and phosphotase content in later growth. Root system flux activity was increased obviously in later grain-filling period by SRI, and was significant or high significant positive correlation with reducing index of canopy leaves, seed setting rate and 1000-grain weight. Therefore, it was suggested that root system flux activity could be used as one of the indicators for high yield cultivation of rice.( 2 ) Under SRI condition, leaf area of single plant was higher than that of TC (traditional cultivation), leaf area index was lower than that of TC at heading stage, but the decling rate of leaf area was slower than that of TC after heading. So SRI could maintenance high photosynthetic potential from heading to ripening. The top 3 leaves of SRI was erecter by SRI than that of TC, and the leaf angle of flag leaf, 2nd and 3rd leaf from top increased in sequence. Therefore, SRI had an ideal plant type, and improved photic gesture of group canopy, increased photis of levels leaf at middle and lower position, improved photosynthetic productivity.( 3 ) Grain yield was significant positive correlation with dry weight at heading and dry matter accumulation after heading. The dry matter weight at jointing stage had no different between SRI and TC. However, the photosynthetic productivity and dry matter accumulation significantly increased at heading and after heading by SRI because of the high chlorophyll content of leaves, and the slow senescence of leaves. This resulted in the biomass of SRI was significant higher than that of TC. SRI also had high export percentage, high export amount and transformation of the matter in stems and shealthes to panicle compared with TC.( 4 ) Under the same cultivation, grain quality had significant different to early or later heading of different tillers per plant. With heading stage retarded, grain quality decreased. Heading duration of gRJ was relatively longer or correspond than that of TC, but SRI can improve grain quality, especially increase milled rice and head milled rice, decrease the percentage of chalky kernel and chalkiness, have no markedly effect on kernel shape.( 5 ) Grain yield of SRI was significantly higher than that of TC. The main reason for its high yield was that SRI by sparse planting with young seeding, were beneficial to increasing individual tillering potential, and improving effective tiller rate, raising transmittance of population, improving panicle characteristics, promoting seed setting rate and 1000-grain weight, so increasing grain yield. On the condition of this experiment, the suitable planting density by SRI was 90,000 to 135,000 plant per hectare.These results indicated that SRI with the coordination with suitable planting density and cultivars with higher tillering potential was an important culturing practices of high-yielding and good-quality in rice. And some problems of SRI that need to be resolved in the production practice of Sichuan were brought forward.