| With global warming, we should not only try to make use of the positive effects, but also pay attention to the associated extreme weather conditions. In recent years, high and low temperate weather conditions have been frequent in Heilongjiang Land Reclamation Region, negatively affecting rice growth and yield formation to a certain extent. This requires integrated management practices to improve rice growth and development environment to reduce yield loss in production. This paper took high and low temperature weather conditions in Jiansanjiang rice production as examples, transplanting density, diagnosis-based nitrogen management and alternate wetting and drying irrigation were integrated to manage rice in response to the year-specific weather conditions. This study determined the weather types based on the accumulated temperature≥10℃for key rice growth periods (effective tillering stage, panicle development stage and grain filling stage), and developed high yield and high efficiency adaptive management systems accordingly and evaluated them. There were five treatments in this study, including CK (no N fertilizer), PF (farmer’s practice),RORM (regional optimum rice management), CM-PRM (chlorophyll meter-based precision rice management) and GS-PRM (GreenSeeker sensor-based precision rice management). The main results are as follows:The commonly planted variety in Jiansanjiang (11leave) requires accumulated effective temperature of2305.1℃for safe maturity. The effective tillering stage needs40days and750.4℃effective accumulated temperature (≥10℃), with average daily temperature of18.8℃. On average, the growth of one leave needs7.7days. Panicle development stage needs30days and accumulated effective temperature (≥10℃) of650.3℃, with an average of6.3days for the growth of one leave and daily average temperature of21.7℃. Grain filling stage requires45days and904.4℃of accumulated effective temperature (≥15℃), with average daily temperature of20.1℃. High yield year had more effective panicles per unit area, effective tillering stage had normal or slightly higher accumulated temperature (≥10℃), and later stages had more days with effective accumulated temperature≥15℃, and had better grain filling. Low yield year was on the contrary.Weather type determination (for11leave variety) was mainly based on accumulated temperature≥10℃, with sunshine hours and rainfall as secondary factors. If the accumulated effective temperature (≥10℃) is>802.5℃, it is likely to have high temperature, and if it is<697.2℃, then it is likely to have low temperature. If the accumulated temperature (≥10℃) in the panicle development stage is>704.4℃, it is likely to have high temperature, while if it is<589.8℃, then it is likely to have low temperature phenomenon. If the accumulated temperature (≥15℃) is less than813.5℃during the grain filling stage, it is likely to experience low temperature, and early maturity varieties should be selected. If it is greater than1038.9℃, it indicates the possibility of late frost during the grain filling stage, and high yielding late maturity varieties can be selected. Therefore, in Jiansanjiang rice production,11leave varieties should be selected, and in high yield exploration fields, high yielding fast grain filling12leave varieties can be selected.Different climate types all have certain influences on rice growth, development and yield. The yields in the years with high temperature in early stage and rainy and less sunshine hours during middle and late stages or with low temperature in early stage and high temperature in the middle stage and normal weather in late stage were reduced by15.3%and5.5%. respectively. High yield high efficiency adaptive management system increased yield by10.3-10.6%, but was not significantly different from the regional high yield high efficiency management. For tiller and plant dynamics, the two abnormal climate types had lower number of tillers at peak tillering stage than normal climate, while high yield and high efficiency adaptive management significantly increased harvested panicles. The LAI was reduced by8.1%and4.0%compared with the largest LAI in normal climate year, respectively, while high yield and high efficiency adaptive management increased LAI over farmer’s practice by10.4%and10.2%, respectively, and increased5.8%and4.3%over regional high yield high efficiency management, respectively. The dry matter accumulated was reduced by25%and11.8%compared with normal climate year, respectively, while high yield and high efficiency adaptive management increased dry matter accumulation by9.3%and7.9%, respectively, as compared with farmer’s practice. Plant N uptake was reduced by17.8%and2.1%respectively, as compared with normal climate, while high yield and high efficiency adaptive management increased10.6%and8.4%, respectively, as compared with farmer’s practice. The transportation and relocation of dry matter was smooth between source and sink of stem and sheath, but not in leaves, indicating that the dry matter accumulated in leaves was not completely converted to rice yield, while high yield high efficiency adaptive management could reduce this gap and further synchronize the relationship between source and sink in leaves.The evaluation of high yield high efficiency adaptive management technologies under different types of climate realized81.9-89.3%of yield potential, and increased yield and economic benefits by7.6-9.9%and2218-2991yuna/ha over farmer’s conventional management. respectively. The recovery efficiency, agronomic efficiency and partial factor productivity of N were increased by59.4%,79.1%and50.4%, respectively, as compared with farmer’s practice. Significantly increased irrigation water use efficiency and reduced lodging risks. For rice grain quality, the milled rice rate and amylose content were increased, rice milling quality, taste quality, appearance quality and nutritional quality were improved and the chalky grain rate and protein content were reduced. |
