Effects Of Sowing Date And Film Mulching On Yield And Quality Of Different Upland Rice Varieties

[Objective] Compared with conventional rice,upland rice has the characteristics of drought tolerance and water saving,and has a better application and popularization prospect in arid and deficient areas.However,the related drip irrigation cultivation techniques for planting upland rice in arid regions are still lacking.In this study,two upland rice varieties were selected,and the effects of sowing date and film mulching on the growth,nutrient absorption,yield and quality of upland rice were discussed.The suitable sowing date for upland rice planting in the study area was proposed.It provides a certain theoretical basis and practical guidance for the cultivation and extension of upland rice in arid areas.[Methods] Two upland rice varieties of Hanxiang No.1 and No.2 were selected,and different sowing dates and film mulching treatments were set.The sowing period is divided into three processes: the first sowing period(April 15),the second sowing period(May 1),and the third sowing period(May 15);under each sowing period,there are two methods of setting: film mulching and bare land.[Result](1)Under different sowing dates,the soil temperature of 5 cm under film mulching increased by 1.7 ?-2.3 ? than that of bare land;the soil humidity of 0-20 cm increased by 15.7%-17.7%.Under the conditions of the first and second sowing periods,film mulching can shorten the growth period of upland rice by 5-8 days;while under the conditions of the third sowing period,film mulching has no effect on the growth period of upland rice.(2)There were no significant differences in the dry weight of aboveground and root systems of Hanxiang No.1 and No.2.Under different sowing dates,the dry weight of the aboveground and root system under plastic film mulching compared with the bare land increased by 11.2% and 35.0% respectively.Under film mulching conditions,the dry weight of the aboveground parts in the second sowing period was increased by 17.5% and 12.2% compared with the first and third sowing periods respectively;the dry weight of the roots of the second sowing period increased by 30.1% and 14.9% than the first and third sowing periods respectively.(3)There was no significant difference in nitrogen,phosphorus,and potassium nutrient uptake between the two upland rice varieties.Under different sowing dates,Compared with the bare land,the absorption of nitrogen,phosphorus and potassium of the two varieties covered with film mulching treatment increased by 43.5%,51.2% and 27.5% respectively;Among the film mulching conditions,the amount of the nitrogen?phosphorus and potassium nutrient absorption was significantly higher in the second sowing period than that in the first and third sowing periods.(4)Under different sowing dates of two upland rice varieties,film mulching compared to bare land significantly increased the number of ears and yield of upland rice,which increased by 15.0% and 21.2% respectively.Under film mulching conditions,the number of spikes in suitable seeding treatments increased by 6.0% and 5.5% respectively,which compared with early and late seeding treatments;the yield of thesecond sowing period treatments which compared to the first and third sowing treatments increased by 18.7% and 9.3% respectively.(5)Under different sowing date conditions,the percentage of polished rice and protein content of Hanxiang No.1 and No.2 film mulching treatments were increased by 2.8 and 0.7 percentage points compared with bare land,respectively.Under the film mulching condition,the percentage of polished rice in the second sowing treatment was 7.7 and 4.7 percentage points higher than that in the first and third treatments,respectively;the protein content of the second sowing treatment was 1.4 and 0.9 percentage points higher than in the first sowing and third sowing treatments,respectively.[Conclusion] Film mulching can increase the temperature and humidity of surface soil in the early stage of upland rice growth,promote the growth of upland rice,shorten the growth period,and increase nutrient absorption and yield.Under film mulching conditions,the yield and quality of upland rice in the second sowing date were significantly better than the first and third sowing date.Therefore,film mulching and the second sowing date are effective measures to improve dry rice yield and quality in arid regions.