Effects Of Ridge And Furrow Planting On Soil Respiration In Wheat Field And Growth Of Winter Wheat

Greenhouse gas emission is one of the most serious global environmental problems that people are facing now.Farmland is a vital source of greenhouse gas,and CO₂ is one of the main greenhouse gases.The ridge-furrow planting is an effective and important technique,which plays an important role in agricultural production in dry areas.However,the way ridge-furrow planting affects soil carbon emission is poorly understood.Therefore,the field experiment was conducted between 2014 and 2016.Conventional flat planting?CP?and three ridge-furrow plantings with alternating ridge/furrow ratios,i.e.20:40cm?P40?;30:30cm?P30?;40:20cm?P20?,were performed in this study.The soil respiration,soil temperature and moisture,winter wheat growth and yield among these four treatments were measured.This research can serve as the basis for meeting greenhouse gas reduction target,designing proper and effective farmland management practices.The main research results are as below.?1?Soil respiration in four planting patterns decreased to its minimum value during the wintering stage,and increased during the reviving stage before it reached a peak value at flowering stage.Soil respiration in three ridge-furrow plantings patterns was higher than that in CP during the seedling stage and wintering stage.In addition,soil respiration of CP rose gradually,and was higher than that of P30 and P20.Soil respiration of P40 was the highest during the winter wheat growing season?except for the reviving-jointing stage?.?2?Compared with CP,ridge-furrow planting demonstrated higher soil temperature during seeding stage and wintering stage.Moreover,three ridge-furrow planting patterns showed significant effect on preserving soil water storage in comparison with CP.And this effect increased with the increase of the ridge width.The magnitude of soil volumetric moisture content in four planting patterns followed this rule: P40>P30>P20>CP.However,the ridge-furrow planting promoted the consumption of deep soil water,which resulted in lower soil profile moisture in the deep soil than the CP did.In the dry year,the more width of the ridge was increased,the lower soil profile moisture was stored compared to the CP.?3?The effects of soil temperature and moisture on soil respiration were synergistic.The correlation analysis indicated a significant positive correlation between soil respiration and soil temperature?P<0.01?,while the correlation between soil respiration and soil moisture was weak.Temperature sensitivity coefficient?Q10?ranged from 1.57 to 1.95,which depends on water in two years.Soil temperature changes can explain the seasonal variation of soil respiration by 34.1%-68.2%.The quadratic model combined soil moisture with soil temperature can explain the soil respiration variation by 59.9%-74.1%.The effects of soil moisture and temperature on soil respiration should be considered synthetically.?4?Grain yield of winter wheat increased significantly under the ridge-furrow planting.The ridge-furrow planting could improve soil hydrothermal conditions to promote wheat growth,and improve the unit area of stem number,LAI and biomass accumulation of winter wheat.The wheat spike number per hectare in two winter wheat growing seasons followed this rule: P40>P30>P20>CP and P40>P20>P30>CP respectively.Compared with CP,the ridge-furrow planting improved wheat yield by 14.9%⁴2.5% in the year when the annual rainfall was sufficient,whereas in the dry year,it can improve wheat yield by 52.1%⁵9.6%.P40 acquired the highest yield and yield increasing proportion among the three ridge-furrow planting treatments.?5?The ridge-furrow planting can collect uneffective rainfall and reduce soil evaporation,which can increase the soil moisture use efficiency and improve WUE eventually,compared with CP,the ridge-furrow planting improved WUE of winter wheat by 11.0%³7.4% in the wet year and by 50.1%⁷2.6% in the dry year.?6?The ridge-furrow planting increased the accumulative CO₂ emission while decreased the CO₂ emission intensity in wheat field,compared with CP.The CO₂ emission intensity during winter wheat growth season in 2014²015 followed this rule: CP>P20>P40>P30,but no significant difference was found among each other.While in 2015²016,the CO₂ emission intensity followed this rule as CP>P30>P20>P40,and it was significantly lower in three ridge-furrow planting patterns than in convention planting.