Effects Of Earthworm Feces Produced In Oilseed Rape Fields On Yield Formation And Eating And Nutritional Quality In Rice

In order to investigate whether earthworm feces in oilseed rape field is related to grain yield and quality of rice and nitrogen uptake of rice plant under no-tillage direct seeding mode of"rice-oilseed rape"rotation.The micro-plot field test was arranged by using split block design with three or four replications in Yunyuan Base of Hunan Agricultural University in both 2016 and 2017.The micro-plot was surrounded by PVC board to form a bottomless frame with an area of 40 cm×40 cm.In 2016,nitrogen application rate（N₁:9 g/m² and N₂:12 g/m²and N₃:15 g/m²）was taken as the main plots,and earthworm casts（EC₀:0 kg/m²,EC₁:17 kg/m²）was taken as the subplots.In 2017,four varieties（Longliangyou 97,Xiangliangyou 396,Liangyoupeijiu and Huang Huazhan）were taken as main plots and earthworm feces（EC₀:0 kg/m²;EC₁:17 kg/m²）were taken as subplots under one nitrogen level.The results showed:1)The effect of earthworm casts application on rice yield and yield components were significant（p<0.05）.The earthworm manure application increased the rice yield by 31.7%,the effective panicle of rice by 21.4%,and the amount of spikelets per unit area by 27.7%,but had no significant effect on the spikelets per panicle,grain filling percentage and grain weight,in 2016.And the rice yield,the effective panicle number,the spikelets per panicle,the grain weight and the amount of spikelets per unit were increased by 18.0%,9.8%,5.5%,1.9%,15.7%,respectively,under earthworm casts treatments.But the effect of earthworm manure application on grain filling percentage was not significant（p>0.05）,in 2017.2)The application of earthworm manure significantly（p<0.05）increased the leaf area index and the dry matter at full heading stage and maturing stage,but had no significant（p>0.05）effect on harvest index.Application of earthworm manure significantly increased the leaf area index and the dry matter by 31.6%and 28.6%,respectively,at full heading stage.And the dry matter at maturing stage was increased by 26.6%,in 2016.Application of earthworm manure significantly increased dry matter by 17.9%at maturity stage of rice in2017.3)Earthworm manure application extremely significantly（p<0.01）increased the total nitrogen uptake and soil nitrogen uptake of rice plants,but had no significant effect（p>0.05）on fertilizer nitrogen uptake and nitrogen utilization efficiency.Earthworm manure application increased the total nitrogen uptake of rice plants by 26.77%,and increased the nitrogen uptake from the soil by 32.4%.4)The effects of earthworm manure application on the contents of cystine and methionine in rice were significant（p<0.05）,but not on the rest of the contents.Earthworm manure application significantly（p<0.05）increased amylose content in rice,but had no significant（p>0.05）effect on protein.The highest viscosity,the lowest viscosity,the alkali elimination value,the gelatinization temperature,the recovery value and the disintegration value of rice were significantly affected,but the effect on the final viscosity and peak time of rice was not significant by earthworm casts.In a word,earthworm casts containing rich nutrient promoted the nitrogen absorption of rice plants,increased the leaf area index,effective panicle and dry matter of rice,and maintained a high harvest index on this basis,thus increasing the rice yield.At the same time,the application of earthworm feces can improve the quality of rice nutrition.