| Agricultural organic materiasls was an important resource.The combined application of organic materials and mineral fertilizer was considered as an important agricultural production practice in increasing productivity,reducing fertilizer consumption and protecting environment in the future.A large number of environmental problems resulting from agriculture production have received considerable attention,such as the excessive use of chemical N fertilizer,insufficient agricultural organic fertilizer recycling.In this research,three kinds of organic materials?straw,cattle manure,mushroom residue?were chosen to add in field combined with the various N application levels?90%?80%?70% pure nitrogen of CK?.The physical and chemical character of soil,the growing situation of wheat in different treatments and yield of wheat were measured.A field experiment was conducted to study the effects of organic materiasls with reducing nitrogen fertilizer on the carbon,nitrogen,water footprint,global warming potential and ecological service value of wheat ecosystem.The results were as follows:1.Returning organic materials to field contributed to increase soil organic matter content,improve soil fertility.Different organic materiasls treatments significantly increased soil urease and inverses activity in the whole growth period of wheat,soil urease activity of the organic materiasls treatments was increased obviously in the flowering period,increased soil urease activity by 1.55%-7.03%.The application of organic materiasls and nitrogen fertilizer significantly increased the soil respiration rate,and soil respiration rate under JFN2 was up to3.30?mol·m-2·s-1.Combined application of organic materiasls and chemical fertilizations were conducive to increase the amount of crop carbon sequestration,reducing greenhouse gas emissions,significant reduce global warming potential of wheat ecosystem.Organic materiasls combined with nitrogen fertilizer can effectively reduce the greenhouse effect of agriculture on global warming.2.Organic materials to field contributed to the accumulation of soil total nitrogen.Returning organic materials to field significantly increased the nitrogen accumulation in the flowering stageand the jointing stage,increased nitrogen accumulation by 12.52%-34.02% and 17.79%-71.09%,respectively.Three kinds of organic materials with nitrogen obvious increased the nitrogen partial productivity than CK,the nitrogen use efficiency of J treatment significantly increased compared with JF and JZ.Organic materials to field can improve nitrogen harvest index in the differently degree.The water preservation capacity of the soil has been considerably strengthened by organic fertilizer treatments.Different organic materials treatments reduce the total water consumption,markedly improved the water use efficiency and water use efficiency of irrigation.Compared with CK,organic materials coupled with N application obviously enhanced the wheat population number,dry matter accumulation,and increased chlorophyll content and maintained higher level of flag leaf photosynthetic rate.Organic materials with nitrogen fertilizer evidently increased grains per spike,1000-grains weight,and significantly increased wheat grain yield,the effect of JF was the most significant under reduced nitrogen fertilizer 20%,and wheat grain yield under JFN2 was up to 6853.43 kg·hm-2.3.In the field of carbon input,organic materials treatments significantly reduced the total carbon emissions,significantly increased the total carbon absorption and ultimately reduced the carbon footprint of farmland ecosystem under reduction of nitrogen fertilizer.The production of nitrogen footprint was reduced under reduction of nitrogen fertilizer,the nitrogen footprint was increased with the addition of organic materials,and the nitrogen footprint was significantly reduced.Ash water is the largest proportion of water consumption in production.The addition of organic materials could reduce the production of green water consumption and the production of ash water,and ultimately reduced water footprint,reduced nitrogen accumulation by8.82%-23.53%,the effect of three kinds of organic materials was better than that of reducing nitrogen fertilizer at the level of 20%.4.Organic materials treatments could increase agricultural service value,the value of clean environment,climate regulation,soil organic matter accumulation function value,water conservation value of the ecological system.Compared with CK,organic materials coupled with N application significantly raised the total ecological service value,and organic materials treatments had the better effect under reduced nitrogen fertilizer 20%.In summary,returning organic materials and reducing the amount of N fertilizer strengthened the water preservation capacity of the soil,improved the accumulation of soil total nitrogen andorganic matter,the soil fertility can be improved;Organic materials treatments increased the chlorophyll content and photosynthetic rate,promoted dry matter accumulation and nitrogen accumulation of wheat,and improved the utilization efficiency of water and nitrogen.Organic materials treatments without a decrease of crop production under reduced nitrogen fertilizer,while carbon,nitrogen and water footprint were obviously decreased,global warming potential was significantly reduced,and the total value of ecosystem services was significantly increase in wheat field ecosystem,and organic materials treatments had the better effect under reduced nitrogen fertilizer 20%,and the total value of ecosystem services of JFN2?JZN2 and JN2 treatments was54036.16?64221.59 ? 45257.08 yuan·hm-2,respectively. |
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