Effect Of Ridge And Furrow With Different Width And Density On Soil Water Heat And Yield Of Spring Maize In Semi-arid Area

Ningnan is a typical semi-arid farming area.The drought-collecting and moisture conservation planting technology of ridge and mulch furrow effectively improves the limitation of drought-cold climate for spring maize production in this area.In order to explore the influence between the coverage ratio and density on soil hydrothermal conditions and spring corn yield.A two-year(2017 was a dry year,2018 was a wet year)field experiment were conducted with twelve treatments,which included three different coverage ratios: ridge and furrow width respectively 80 cm:40 cm(R8F4),60 cm:60 cm(R6F6)and 50 cm:10 cm(R5F1),the traditional bare the culture(CK)as contrast.Addtionally,we set up three densities: 67500 plants/ha(L),82500 plants/ha(M)and 97500 plants/ha(H),to study the influence of different coverage ratio and density on soil moisture,temperature,maize growth,canopy characteristics,yield and WUE.The main results were as follows:(1)Influence of ridge structure and density on soil moistureRidge and furrow structure directly affects the area of rain-collecting ridge and planting furrow,and then affects the effect of water collection and soil water storage.In the 60d(jointing stage)after maize sowing,the soil water storage of 0-200 cm under R8F4,R6F6 and R5F1 treatments in 2017 increased by 4.7-13.0 %,5.1-8.7 % and 12.9-15.0 %,respectively,compared with CK treatments.In 2018,it will increase by 2.6-12.3 %,1.8-9.6 % and 7.6-14.7 %.At 150 d after maize sowing(maturity stage),soil water storage in 2017 reached the maximum value in the whole growth period,and the differences of planting methods were not significant.In 2018,the soil water storage amount in different ridge and furrow rain-harvesting planting was significantly higher than CK.The soil water storage in the 0-200 cm soil layer for two years showed a consistent rule: under the same planting mode,the soil water storage decreased with the increase of density;Under the same density condition,soil water storage increased with the increase of furrow cover ratio.(2)Influence of ridge and furrow structure on soil temperatureUnder different ridge and furrow structures,soil temperature in the 0-25 cm soil layer increased with the increase of furrow and furrow coverage ratio,among which the temperature increase in the early growth stage of corn was large and the difference was obvious,but the difference was not obvious in the later growth stage.Ditch rainwater harvesting R8F4,R6F6,R5F1 each processing corn 0-25 cm soil fertility period average temperature respectively than CK increased 0.68 ℃,0.31 ℃ and 1.43 ℃,0-90 d after seeding respectively than CK increased 1.42 ℃,0.93 ℃ and 2.76 ℃.Three in a ditch planting mode under the ridge soil temperature increased 2.6 ℃,2.1 ℃ and 0.5 ℃.After sowing of 0-90 d arable layer soil temperature is 90-150 d after seeding significant high 1.46-4.12 ℃.(3)Effects of ridge and furrow structure and density on the growth and population characteristics of spring maizeUnder the same density,the height order of spring maize plants was R5F1>R8F4>R6F6>CK.In the same furrow planting method,spring corn plant height decreases with the increase of density.During the growth period,LAI of R8F4,R6F6 and R5F1 increased by 98-120.5 %,94.8-102.1 % and 106.6-125.2 % respectively compared with CK treatment in 2017.they increased by 24.9-37%,15.7-27.7 %,31.5-41.7 % respectively in 2018.Under the same ridge planting mode,LAI in the two years decreased with the increase of density,and increased with the increase of ridge coverage ratio under the same density.In 2017,the dry matter accumulation in R8F4,R6F6 and R5F1 ridges and furrows increased by 102.3 %,82.6 % and 110.3 % respectively compared with CK treatment,and increased with the increase of density.In 2018,each rainwater harvesting treatment increased by 16.1%,10.7 % and 19.9 % respectively,compared with CK treatment,and dry matter accumulation reached the maximum under M density.Compared with CK,the light transmittance of R8F4,R6F6 and R5F1 decreased by 24.9 %,38.7% and 47.5 % respectively.The light transmittance of R8F4 rows was 17.6 % and 27.2 % higher than that of furrow row(P<0.05).R6F6 treated rows were decreased by 14.1 % and 10.6% respectively.In 2017,the light transmittance of M and H decreased by 20.2 % and 24.9 % respectively compared with that of L and M.It was down 24.2 % and 29.1 % in 2018.(4)Influence of ridge structure and density on yield and WUE of spring maizeIn 2017(dry year),the grain yield of ridges and furrows treated with R8F4,R6F6 and R5F1 was significantly increased by 222.2 %,131.0% and 229.1 % respectively compared with CK treatment.In 2018(wet year),they have increased by 23.9 %,18.3 % and 25.9 % compared respectively with CK(P<0.05).The kernel number per ear and 100 kernel weight of two-year maize were the highest under R5F1 treatment.The grain yield was expressed as M>L>H.In 2018,the WUE of R5F1,R8F4 and R6F6 furrow rainwater harvesting treatment was significantly increased by 23.2 %,23.6 % and 13.2 %,respectively,compared with CK.The WUE of different densities in the two years were all in the order of M>L>H,in which the WUE of M density was significantly increased by 6.4 % and 9.5 %,respectively,compared with that of L and H.In conclusion,compared with traditional bare soil,ridge and furrow rainwater harvesting treatment can significantly improve soil water and heat condition and increase yield and efficiency.According to the analysis results of ridge structure and density,R5F1 and R8F4 treatment under M density significantly increase dry matter accumulation and increase grain yield and WUE,which are recommended for local production.