RESPONSE OF PHYSIOLOGICAL GROWTH CHARACTERISTICS OF RICE TO DIFFERENT BIODEGRADABLE MULCHING AND IRRIGATION METHODS IN COLD REGION OF NORTHEAST CHINA.

To reveal the mechanism of influence of different types of biodegradable plastic film mulching and irrigation combinations on the physiological growth characteristics of rice in cold regions, eight types of film mulching irrigation methods were designed, which combined four types of plastic film mulching and two types of irrigation methods for a total of nine treatments. The study analyzed the degradation law of degradable plastic film in rice fields in cold regions, and the effects of film-mulching irrigation methods on rice photosynthetic characteristics, dry matter transport, and rice yield. The results showed that the three biodegradable plastic films were suitable for the rice fields in the northeast cold region. Except for the jointing stage, mulching irrigation treatments could increase the chlorophyll content and net photosynthetic rate of rice, and the improvement degree showed a downward trend with the growth of rice. The film mulching irrigation treatments improved rice stems and leaves dry matter transport and grain contribution. The comprehensive evaluation based on the comprehensive index method showed that the combination of ridge irrigation and thin black biodegradable mulch is the best combination of biodegradable plastic film mulching and irrigation in the study area. [ABSTRACT FROM AUTHOR]