Effects Of Straw Mulching And Biochar On Soil Moisture,Soil Temperature And Maize Yield

The application of straw mulching for agricultural production not only provides an effective way for the utilization of crop straw resources,but also puts an end to the environmental problems caused by straw burning.Biochar is a carbon-containing product,produced by the pyrolysis of waste straw and other biomass.Field experiment was carried out to study on the application of straw mulching and biochar on soil hydrothermal status,maize plant height,dry matter accumulation and distribution,leaf area index,leaf chlorophyll,stem diameter,yield and water use efficiency of maize in rainfed areas in northeast China.The whole experimental field was divided into two main plots which received 0 t·hm^-2?F₀?and 8t·hm^-2?F₁?of straw mulching.Each main plot was divided into 3 subplots which received 0t·hm^-2?C₀?,4 t·hm^-2?C₁?and 12 t·hm^-2?C₂?of biochar.The results showed that:?1?Straw mulching?F₁?treatment had a significant impact on soil moisture and temperature,and significantly improved the soil moisture content of 0-40cm depth,which was14%higher than F₀.Average soil moisture content of 0-60cm was 10.4%higher than that of Straw mulching significantly reduced the temperature of 0-25 cm soil layer,especially in 5and 10 cm soil.The maximum temperature drop effect is 13.43%lower than that of F₀,the F₁treatment of the temperature drop effect in the growth period shows a large change trend in the early stage and a small change trend in the later stage,14.13%lower than that of F₀.The effect of biochar C₁and C₂treatment on soil moisture and temperature were not obvious,but all biochar treatment improved soil moisture content.Under the condition of no covering,i.e.bare land,the biochar has a warming effect,and the ground temperature increases with the increase of the amount of carbon applied.Under the straw mulching condition,the soil layer of 0-10 cm has a cooling effect,while the soil layer of 15-25 cm has a warming effect.?2?Straw mulching and biochar had significant effects on maize growth and development,Straw mulching?F₁?has certain growth inhibition of maize,but as time progress its inhibitory effect weakened gradually and in the middle can obviously promoted the growth of maize,and processing of Plant height,stem diameter,leaf area index,dry matter accumulation and chlorophyll content were increased by7.63%,13.15%,23.02%,11.11%and 7.61%in F₁than in F₀.Biochar significantly promoted the growth of maize at different growth stages,and growth was increased with increasing the rate of biochar.The plant height,stem diameter,leaf area index,dry matter accumulation and chlorophyll content of C₂were increased by 22%,16.8%,36.7%,41.98%and 7.9%,respectively,compared with those without biochar.Overall,F₁C₂treatment showed the best growth characteristics in all treatment combinations,significantly higher than other treatments.?3?Straw mulching significantly improved the yield,yield composition and economic coefficient of jade.The average yield and water use efficiency under F₁treatment was 12%,4.68%?12.98%and 3.94%higher than that of F₀,respectively.Biochar can also significantly improve corn yield,yield composition and economic coefficient.Among all biochar treatments,the overall optimal corn yield,yield composition and economic coefficient of C₂treatment were significantly higher than that of C₀,with an average annual increase of 12.15%,4.48%?9.89%and 11.12%,respectively,compared with that of C₀.In general,the yield,yield composition and economic coefficient of maize treated with F₁C₂were the best,significantly higher than that of F₀C₀.?4?Straw mulching and biochar had significant effects on WUE.The WUE of F₁treatment in the two years was significantly improved by 11.7%compared with that of F₀treatment.Biochar can also significantly improve WUE,and WUE increases with the increase of carbon application amount.The WUE was improved by 7%and 17.5%under C₁and C₂as compared with C₀,respectively.Overall,F₁C₂treatment had the highest WUE than other treatments.In conclusion,straw mulching and biochar treatment can effectively improve the soil water and temperature condition and improve the suitable water and temperature environment for the growth and development of maize.Under the conditions of this experiment,the soil treated with F₁C₂was in good soil water content and temperature,and the yield and water use efficiency were better.