Analysis Of Key Technologies For Jiangsu Province’s Rice Yield Increasing Evenly

Rice is the major grain crops in Jiangsu Province. It is very important to stabilize rice yield for food security strategy in Jiangsu Province. The objective of this paper was to reveal key restrictive factors of rice yield improvement in large area including choose of rice varieties, cultivation methods and key cultivation technologies in Jiangsu Province. Temporal variations of rice yield, unit yield and key meteorological factors in 50 years were analyzed in this study in Jiangsu Province. Further, with field experiments of representative rice varieties in different years and typical investigation in 23 rice production counties, characteristics and regional variation of japonica rice varieties, cultivation methods and cultivation technologies were studied. The results as follows:Based on rice production data of 13 administrative regions in Jiangsu Province, the regional variation in production layout of rice and its influencing factors in the past 50 years were analyzed in this paper. The results showed that rice production increased by 2.9 times during 1961-2010years and the spatial characteristics of rice production were reduction in South Jiangsu area while increase in North Jiangsu area. Elevated rice yield was the key actuation factor which promoted higher rice production; improved rice planting area 12.9% with two peak curves was the basic condition which ensured increasing rice production. In addition, among different regional areas, North Jiangsu was the main area boosted rice production in Jiangsu province, followed by Central Jiangsu area, the third by South Jiangsu area. The tread of rice planting area quick decrease in South Jiangsu area and quick increase in North Jiangsu area were the key factor results of characteristics of rice production large reduction in South Jiangsu area and large spread in South Jiangsu area. Meanwhile, rice yield increased conspicuously, among different region, increase rate in North Jiangsu area was higher than that of South Jiangsu area. Major factors of improved rice varieties and cultivation technology contributed to rice yield greatly, climate change was conducive to higher rice yield in the past 50 years, South Jiangsu area>central Jiangsu area>North Jiangsu area. Basic measures should be carried out to ensured the rice production including increasing rice planting area in North Jiangsu area, keeping it steady in Central Jiangsu area and controlling its decreasing trend in South Jiangsu area, in addition, major path should be drawn up to promote increase of rice yield with breeding high-yielding varieties and innovation cultivation techniques, particularly in North Jiangsu area.Based on rice yield data of 13 administrative regions and meteorological data of 13 meteorological stations in the Jiangsu province, the spatial and temporal variation of meteorological factors in past 50 years and its effects on rice yield in Jiangsu Province were analysis in this paper. The results showed that rice yield increased conspicuously with fluctuation in Jiangsu Province. The average temperature, minimum temperature, maximum temperature from 1960s to the end of 1970s were decreased obviously while opposite after 1980s. Sunshine duration reduced significantly in the past 50 years and the reduction extent in South Jiangsu area was higher than North Jiangsu area. Little changes were detected in rainfall in Jiangsu Province. Above all, climate change on rice production was unfavorable which was most obvious in the South Jiangsu area. Because of low temperature in the North Jiangsu area in the first place, the increase of temperature may have favorable effects on improvement of rice yield.Two years experiments were conducted with ten typical japonica varieties widely planted in Jiangsu Province during the last 50 years which were classified into five groups i.e.1960s,1970s,1980s,1990s and 21st century, according to their breeding times. In this experiment, the characteristics of grain yield and biomass production, nutrient absorption and source-sink relationships were compared. The result showed that (1) grain yield of varieties bred from 1960s to 2000s increased with the evolution of the cultivars, and the yield of 1990s was highest. (2) the nutrient absorption increased from 1960s to 2000s, and in recent years leaf color tend to be "green-yellow-green-yellow", which more suitable for enlarging the yield of Jiangsu province. (3) yield of 2000s’cultivation widely varieties was lower than 1990s. The reason was that the decreasing of growth stage made the LAI and biomass production decreased, and HI increased.The data of rice grain yield and population quality parameters were surveyed from 26 high-yield sites of Jiangsu province. Fields at every site were classified to three ranks according to the yield levels. The results showed that (1) those were dominant of partly yield components at the higher-yield plots, e.g., spikelets per m2, panicles per m2, spikelets per panicle. There were no significant differences in spacing characteristics, which mainly includes row spacing, holes spacing and panicles per hole. (2) There was significant in the uniformity of panicles per hole. The differences of spikelets per panicle mainly were contributed from numbers of secondary branch and the uniformity of secondary branch. There were significant positive correlation between the uniformity of panicles per hole and grain yield (r=0.436**,2009; r=0.441**,2010). (3) The leaf length of top-four leaves were beneficial to enhance the spikelets per panicle, but it could decreased the grain-filling, especially the lower position leaves. These results suggested that it was the most effective path increasing yield balanced that the uniformity of panicle per m2 and spikelets per panicle were increased.The surveys of yield components and the uniformity of population qualities were conducted at 23 high-yield sites of Jiangsu province in 2009 and 2010. The aim of this study was to study the influence of different cultivation methods on rice yield and uniformity of population indices. The cultivation methods included hand transplanting (HT), machine transplanting (MT), throwing seedling (TS), and direct seeding (DS). Yield, yield components and the uniformity of population qualities were measured. In this study, the main factor restricting field was panicles per m2. The yield of direct seeding plots was lower and non-stability due to the worse uniformity of population qualities. As to the throwing seedling plots, the uniformity of holes per m2 and panics per hole were significantly lower than other cultivation methods. The method of machine transplanting was suitable for large-scale extension, which mainly contributed to higher, stable yield and the better uniformity. Thus, the method of machine transplanting could be spread widely depended mainly on the ample panicles per m2 and spikelets per panicle.Japonica rice was planted widely from the north area to south area of Jiangsu province, and it can be divided into three areas namely south of Jiangsu, middle of Jiangsu, north of Jiangsu. In this study, we compared the production of basic elements among three areas under the machine transplanting method. The results showed that there were significantly differences on yield components at different region. Compared with middle of Jiangsu and south of Jiangsu, the panicle per m2 was higher, but spikelets per panicle lower. It was more suitable for machine transplanting method due to the reasonable stage, nitrogen strategies, hole spacing and higher uniformity. This study suggested that decreasing of hole spacing to improve the holes per m2 was the main path of increasing the yield. And there were larger scale to improve yield of north of Jiangsu.