| The black soil region of Northeast my country undertakes the important task of grain production in China.However,for a long time,due to factors such as people’s blind pursuit of crop yield and unreasonable application of chemical fertilizers,the quality of black soil has been seriously degraded and the productivity of the land has been reduced.Therefore,scientific protection and improvement of soil in black soil area are of great significance to the sustainable development of agriculture.China uses only 6.7% of the world’s arable land to feed 20% of the world’s total population.Behind this,chemical fertilizers play a crucial role in increasing food production.However,with the gradual increase in the amount of chemical fertilizer application,excessive application of fertilizer not only reduces the efficiency of fertilizer use and the efficiency of crop yield increase,but also has a very bad impact on my country’s agricultural production and ecological environment.Therefore,how to meet the growth of grain output while reducing the amount of chemical fertilizer application is an urgent problem that my country needs to face to achieve sustainable development of green agriculture.In recent years,studies have shown that straw carbonization is an effective method to avoid waste of straw resources,and promote the healthy development of agriculture while being low-carbon and environmentally friendly.At present,there are many single-factor studies on biochar,but there are still few studies on the effect of biochar and nitrogen fertilizer coupling on water and nitrogen use in black soil areas.Therefore,in 2021,a potted research on the water and nitrogen utilization effect of maize coupled with carbon and nitrogen in the black soil area was carried out in the mobile rain shelter of Northeast Agricultural University located on the typical black soil belt of Northeast China,using the two-factor saturated D-optimal design(206),taking the amount of biochar and nitrogen fertilizer as the experimental factors,a total of 6 treatments were set up,and each treatment was repeated three times.The influence of the above indicators,to clarify the water and nitrogen utilization effect of the maize carbon-nitrogen coupling in the black soil area.The results show:(1)Appropriate amount of biochar combined with nitrogen fertilizer can improve maize plant height,stem diameter and leaf area index.With the growth of maize,the effect of biochar combined with nitrogen fertilizer on the improvement of maize plant height gradually weakened.The effect of nitrogen fertilizer coupling on maize plant height was the strongest at seedling stage,and the weakest at grain filling stage;the improvement effect on maize stalk diameter first increased and then weakened,the effect of nitrogen fertilizer coupling on the improvement of maize stem diameter was the strongest at jointing stage,and the weakest at grain filling stage.Under the condition of C2N3 treatment,the plant height,stem diameter and leaf area index of each growth stage were the highest among all treatments in the same period.Under the condition of constant nitrogen application,when a small amount of nitrogen fertilizer was applied,the application of biochar significantly increased the plant height,stem diameter and leaf area index of maize,and the application of biochar increased the plant height of maize at the seedling and jointing stages.The effect was significantly greater than that in the tasseling and grain-filling stages,and the improvement of maize leaf area index in the tasseling and grain-filling stages was significantly greater than that in the seedling stage and jointing stage;when high levels of nitrogen were applied,appropriate application of biochar had a significant effect on the plant height,stem diameter and leaf area of maize.The area index increased,while excessive biochar inhibited the plant height,stem diameter and leaf area of maize.With the growth of maize,the inhibitory effect of excessive biochar on maize stem diameter and leaf area index became more and more obvious.(2)Appropriate amount of biochar combined with nitrogen fertilizer can improve corn yield,ear length,ear stem,100-grain weight and water use efficiency.Increasing the water consumption modulus coefficient WOC and water consumption intensity DWC at the seedling and jointing stages,and reducing the WOC and DWC at the tasseling and grain filling stages,makes the water consumption process of corn advance and can reduce the water consumption of corn.Under the condition of constant nitrogen application,when a small amount of nitrogen fertilizer is applied,the application of biochar can significantly increase the yield,ear length,ear stem and 100-grain weight of corn;when a higher level of nitrogen fertilizer is applied,appropriate application of biochar has a significant effect on maize yield,ear length,ear stem and 100-kernel weight were improved,and excessive application of biochar decreased maize yield,ear length,ear stem and100-kernel weight.Among the treatments,the corn yield,ear length,ear stalk,100-kernel weight and water use efficiency WUE increased the most in the C2N3 treatment;the water consumption decreased the most in the C3N3 treatment,which reduced water consumption by 7.5% compared with the control treatment.(3)Appropriate application of biochar can improve soil p H value,soil total organic carbon content,available potassium content,alkali-hydrolyzable nitrogen content and available phosphorus content,and application of nitrogen fertilizer can increase soil alkali-hydrolyzable nitrogen content,while reducing soil p H value,Total organic carbon content,available phosphorus and available potassium content.When the nitrogen application rate is fixed at the same level,the application of biochar can improve the soil p H value,soil total organic carbon content and available potassium content.Appropriate application of biochar can increase soil alkaline hydrolyzable nitrogen content and soil available phosphorus content,while excessive The application of biochar will reduce the content of soil alkaline hydrolyzable nitrogen and soil available phosphorus;through factor analysis of 5 soil indicators under different ratios of carbon and nitrogen,the comprehensive score of each treatment factor shows that the treatment with the highest comprehensive fertility score is C2N3 treatment,when soil fertility is most conducive to maize growth.(4)Combined application of biochar with nitrogen fertilizer can improve the total amount of aboveground nutrient absorption,grain nitrogen content and grain nitrogen distribution ratio of single maize plant.Under the same nitrogen application rate,when the nitrogen application rate is fixed at the same level and the nitrogen application rate is low,the application of biochar can increase the total amount of aboveground nutrient absorption and grain nitrogen content of a single maize plant;when the nitrogen application rate is fixed At the same level and with a high nitrogen application rate,appropriate application of biochar can increase the total aboveground nutrient uptake and grain nitrogen content of a single maize plant,while excessive application of biochar can reduce the total aboveground nutrient uptake and grain nitrogen content of a single maize plant.Grain nitrogen content;the total amount of nutrient uptake,grain nitrogen content and grain nitrogen distribution ratio of single maize plant increased the most in the C2N3 treatment.Under the same carbon application rate,the nitrogen absorption efficiency,nitrogen fertilizer apparent utilization rate,nitrogen fertilizer partial productivity,nitrogen fertilizer agronomic efficiency and nitrogen use efficiency of each carbon-nitrogen coupling treatment decreased with the increase of nitrogen application rate;Under the same conditions,the nitrogen absorption efficiency,apparent nitrogen utilization efficiency,nitrogen partial productivity,nitrogen agronomic efficiency and nitrogen use efficiency of each carbon-nitrogen coupling treatment showed a quadratic parabolic curve trend with the increase of carbon application rate.The nitrogen absorption efficiency and nitrogen partial productivity reached the maximum in the C1N1 treatment,and the nitrogen apparent use efficiency,nitrogen agronomic efficiency and nitrogen use efficiency were the largest in the C2N3 treatment. |
PDF Full Text Request