Study On The Relationship Between Rice Storage Quality And Fertilization Modes Of Rice-crab Culture System

With the continuous improvement of economic life,people's requirements for the quality of rice,one of the main food crops,have become stricter.Fertilization mode is one of the important factors affecting rice yield and quality.After the country put forward the concept of developing green and sustainable agriculture,a typical rice ecological breeding mode of rice-crab culture has been developed in Panjin area of Liaohe River Basin in recent years,which can improve the ecological environment and bring greater economic benefits.From a food perspective,both rice yield and quality,which are closely related to the fertilization mode,should be considered.In this study,Yanfeng 47 rice varieties are used as materials.The effects of three typical fertilization modes on rice yield,post-harvest quality and quality changes during storage are studied,which provides a theoretical and practical basis for selecting suitable fertilization mode for rice-crab culture system.At the same time,the quality and quality index of 16 farmer samples from rice-crab field and crab-free field is measured in this study,in order to visually show the effect of rice-crab culture system on the comprehensive rice quality.Results are as follows:1.Rice yield and post-harvest qualityIn this study,three local optional fertilization modes,namely traditional mode FP1(fractional application of inorganic fertilizer),one-time application of mixed organic and inorganic fertilizer FP2,and one-time application of inorganic fertilizer OPT(soil testing formula fertilization),are evaluated for both rice yield and quality.The results show that in the rice-crab culture system,FP2 uses fewer fertilizers and has a lower economic cost,and the yield is only slightly less than that of OPT,which is 9377 kg·hm-2,with no statistical difference.For the post-harvest quality of rice,the milling quality of FP1 is the best,and the cooking and eating quality is the worst.FP2 has the best appearance quality and cooking and eating quality,and has the most amino acid content.The proportion of essential amino acids is the highest,reaching 33.08%.All three fertilization modes significantly reduce the amylose content and increase the protein content of rice,with the least change in FP2.There is no significant change in crude fat content compared with the control group.2.Quality changes of rice during storageDuring storage,FP1 exhibits better milling quality.The brown rice rate changes little,the milled rice rate decreases,and the head rice rate increases slightly during storage.The milling quality of rice in the rice-crab culture system was improved during storage;Of the three fertilization modes,the appearance quality of FP2 is better.Rice appearance quality is improved during storage in the rice-crab culture system;Of the three fertilization modes,the cooking and eating quality of FP2 is the best,and the rice eating quality in the rice-crab culture system decreases little during storage;Fertilization resulted in a significant decrease in amylose content,a significant increase in protein and amino acid content,and no significant change in crude fat content.FP2 fertilization mode elicits the lowest amount of proteinincrease and amylose reduction,and the most amount of amino acid increase,which has the best nutritional quality.During the whole storage process,the amylose,protein and amino acid content do not change significantly,and the crude fat content decreases slightly;The changes of fatty acid value,water content and total number of colonies during storage are mainly affected by the storage temperature and humidity,and the differences among different samples are not significant.During storage,the content of MDA is first increasing and then decreasing.3.Differences in quality and quality index of rice samples from farmers under rice-crab and crab-free systemCompared with crab-free field,rice milling and appearance quality are better in rice-crab culture system.The rice-crab culture system has little effect on the cooking quality of rice,but it can slow down the deterioration of the eating quality of rice during storage.The rice-crab culture system has little effect on the texture and starch gelatinization properties of rice,and can increase the amount of essential amino acids and total amino acids in rice.The rice-crab culture system can slow down the degree of lipid oxidation of rice during storage and play a certain role in inhibiting the growth of bacteria.The results show that the rice quality index decreases during storage.The average quality index of rice in rice-crab system(92.08% and 87.34%)before and after storage is higher than that in crab-free system(91.75% and 86.53%).After storage,the drop in the rice quality index of the rice-crab field is 9.49% lower than that of the crab-free field.,which proves that rice-crab ecological cultivation can improve the overall quality of rice and slow down the deterioration of rice quality during storage.Taking into account the rice yield and post-harvest quality under the rice-crab culture system,we believe that the FP2 fertilization mode significantly increases rice yield and improves rice quality.And during storage,the rice under FP2 fertilization mode still maintain a good appearance quality,cooking and eating quality and nutritional quality.Therefore,we believe that the FP2 fertilization mode is the best choice for rice-crab culture system in Panjin area.At the same time we should pay attention to avoid rice storage in high temperature and humidity environment,so as not to accelerate the deterioration of rice quality.