Effect Of Silicon On Soil Nutrient Availability And Nutrient Uptake Of Rice Under Low Temperature Stress

Rice is the main grain crop in northeastern China.The great loss of output caused by severe low temperature and the cold damage threatens the food security in the region.Silicon application can enhance the stress resistance of rice and thus resist low temperature stress.In this experiment,the main cultivated japonica rice variety Dongnong 427 was used as a potted experimental material and was treated with artificial climate chamber for low temperature stress.Five kinds of silicon preparations were selected: Si-50(aminopropyltriethoxysilane)and Si-60(3).-Glycidyloxypropyltrimethoxysilane),Si-RH(rice shell extract),Si-50-G(amino-containing nanosilica),Si-60-G(epoxy-containing nanosilica)),Foliar spraying during the tillering stage of rice,and the control CK(equal distilled water).At the tillering stage,low temperature stress treatment and room temperature treatment were respectively performed to determine the content of available silicon,amorphous silicon,water-soluble silicon,active silicon,alkali-hydrolyzable nitrogen,available potassium,and quick-acting phosphorus in the soil during the tillering and maturing stages of rice.The contents of available silicon,total nitrogen,total potassium,and total phosphorus in rice plants,rice yield and compositional factors at the maturity stage(plant height,effective panicles,grains per spike,seed setting rate,and 1000-grain weight).The effects of different types of silicon preparations sprayed at the delivery stage on the effects of different temperature conditions on the morphology of soil silicon,nutrient availability,nutrient absorption and yield of rice were studied.In order to reveal the physiological effects of silicon preparations on rice under low temperature stress and elucidate the mechanism of its regulation on crop nutrient absorption,it provides theoretical and experimental support for the regulation of silicon nutrition under low temperature stress conditions.Research indicates:Different silicon formulations can improve the state of soil silicon under low temperature stress.The soil available silicon,amorphous silicon,water-soluble silicon and active silicon content increased significantly by 4.48%-8.53%,40.73%-73.14%,15.61%-51.71% and 11.24%-24.50%,respectively,during the tillering period.Among them,Si-60-G has the best effect on the increase of soil active silicon in the soil,such as effective silicon,amorphous silicon,Si-RH on soil water-soluble silicon,and Si-50-G to get soil active silicon.(2)Different silicon formulations can increase the soil available nutrient content under low temperature stress.The contents of alkali-hydrolyzable N,available K,and available P in the tillering stage increased significantly by 12.73%-42.18%,7.73%-13.92%,and 14.13%-34.72%,respectively.Among them,Si-50 had the best effect on the content of soil alkali-hydrolyzable nitrogen,Si-60 and Si-50-G on soil available potassium,and Si-60 on the available phosphorus content.(3)Different silicon preparations can effectively alleviate the inhibitory effect of low temperature on rice nutrient absorption at the tillering stage,and promote the increase of rice yield and its constituent factors.Under low temperature stress,all silicon preparations can increase the effective silicon,total nitrogen,total potassium,total phosphorus content,and increase the number of effective panicles,grains per panicle,seed setting rate,1000-grain weight and yield.Among them,the effective silicon,total nitrogen,total potassium,and total phosphorus content in the tiller stage increased significantly by 8.08%-17.47%,17.20%-27.96%,30.00%-94.12%,and 14.59%-33.17%,respectively.Among them,Si-RH had effective silicon,total nitrogen and total phosphorus content in plants,and Si-50-G had the best effect on the increase of total potassium content.The number of effective panicles,grain number per panicle,seed setting rate,1000-grain weight and yield were significantly increased by 3.96%-7.38%,4.89%-19.97%,1.80%-4.59%,0.8%-6.90%,and 6.56%-27.50%,respectively.Among them,Si-60 had the best effect on the number of effective panicles,seed setting rate and 1000-grain weight,and Si-60-G had the best effect on the number of panicles and yield.Therefore,Si-60-G and Si-60 have the best yield increase effect.At the same time,silicon preparations can reduce the plant height by 2.31%-7.59%,of which Si-RH works best.