本文選題：豆科綠肥　切入點：冬小麥　出處：《西北農林科技大學》2016年博士論文　論文類型：學位論文

【摘要】：作為一個典型的雨養(yǎng)農業(yè)地區(qū),我國黃土高原地區(qū)農業(yè)生產的可持續(xù)發(fā)展不斷面臨著水分虧缺和土壤貧瘠所帶來的挑戰(zhàn)。夏閑期種植并翻壓綠肥作物不僅可以有效培肥地力、促進后茬作物生長和產量形成,同時能在時間和空間層面上提高養(yǎng)分、水分、光熱等自然資源的利用率,因此,本研究通過在渭北旱塬地區(qū)開展長期的田間定位試驗(2008年~至今),深入研究黃土高原地區(qū)種植不同豆科綠肥(長武懷豆、大豆和綠豆,夏季裸地休閑為對照)以及冬小麥生長季不同施氮水平(0,108,135,162 kg N/ha)對土壤水分和氮素供應的影響,初步探究豆科綠肥協(xié)調土壤水分和氮素供應的效應及機理,旨在為恢復并發(fā)展我國綠肥產業(yè)體系提供科學的理論依據和技術支撐。取得的主要結果如下:(1)通過4年的田間定位試驗數據,研究發(fā)現旱地連續(xù)多年種植并翻壓豆科綠肥較傳統(tǒng)的裸地夏休閑能夠有效促進后茬冬小麥苗期的生長(冬季單株分蘗數和春季總莖數)、后期的產量形成(產量、生物量和公頃穗數)和養(yǎng)分吸收狀況。然而,由于需要額外的勞動成本和田間管理投入,豆科綠肥體系較高的生產成本嚴重影響該體系的經濟效益。此外,施用氮肥較不施氮顯著提高旱地冬小麥生長狀況、產量形成、養(yǎng)分吸收和經濟效益,然而三種氮肥施用量間無顯著差異;(2)通過6年的田間定位試驗結果并結合當地57年的降雨氣象資料,詳細分析我國渭北旱源冬小麥種植區(qū)降雨時空分布特征,初步研究黃土高原地區(qū)不同降雨年型條件下應用豆科綠肥對后茬冬小麥產量和水分利用效率的影響,同時探究豆科綠肥協(xié)調旱地土壤水分平衡的內在機理。發(fā)現連續(xù)多年夏閑期種植豆科綠肥的確會消耗土壤水分,同時該措施會因降雨年型的不同而對后茬冬小麥產量帶來不同程度的影響。當年降雨量較為豐沛時,種植豆科綠肥所引起的夏閑期土壤水分虧缺能夠得到及時補充,豆科綠肥可增加旱地冬小麥生產量;反之,干旱年份則該措施將帶來嚴重的減產效果。整體來看,試驗期間種植并翻壓豆科綠肥較夏休閑顯著提高冬小麥產量和水分利用率,平均提高幅度分別為13%和27%。同時,豆科綠肥對促進旱地土壤水分平衡也發(fā)揮著重要的作用;(3)結合長達374天的豆科綠肥的腐解試驗,進一步探究了豆科綠肥生育期所累積的氮素在旱地傳統(tǒng)的冬小麥種植體系中吸收、轉化和利用的內在機制。研究發(fā)現,試驗期間平均每年豆科綠肥在其盛花期通過其地上部和根系生物量積累共計53~76 kg N/ha氮素,通過一年的翻壓還田,至少有32 kg N/ha綠肥氮素經過土壤微生物的分解礦化作用釋放到周圍環(huán)境中;其中,約有7~27 kg N/ha最終被后茬的冬小麥吸收利用。整體來看,豆科綠肥體系平均每年氮素總投入量為164 kg N·ha-1·yr-1,氮素攜出量平均為114 kg N·ha-1·yr-1,最終導致該體系每年約有50 kg N·ha-1·yr-1的氮素盈余在土壤中。旱地夏閑期應用豆科綠肥能夠有效替代13~48%(平均為31%)的冬小麥生長季無機氮肥用量。此外,連續(xù)4年種植豆科綠肥可降低夏閑期間土壤硝態(tài)氮向深層(100~200 cm)淋溶的風險,平均降低硝態(tài)氮淋溶19.6 kg N/ha;(4)通過5年的田間試驗結果,探究我國黃土高原地區(qū)應用豆科綠肥對旱地麥田土壤碳庫和氮庫庫容的影響;同時采用One-compartment模型,對土壤有機碳庫周轉的動態(tài)機制進行了擬合。發(fā)現在黃土高原地區(qū)的夏閑期種植短期的豆科綠肥,其生物量及碳、氮養(yǎng)分累積與生長周期呈極顯著的冪函數關系。經過一年的腐解礦化,旱地麥田土壤中豆科綠肥地上部和根系的平均碳素殘留率分別為26%和33%;而相應的平均氮素殘留率分別為31%和52%。與基礎土樣相比,夏閑期連續(xù)多年種植并翻壓豆科綠肥顯著提高旱地麥田表層土壤有機碳、活性有機碳和全氮含量以及相應的庫容儲量。此外,試驗第5年表層土壤有機碳庫儲量與平均每年作物碳還田量間呈現顯著的正相關關系,并且每年至少需要0.68 Mg C·ha-1·yr-1的作物碳還田量才能夠基本維持基礎土壤的有機碳庫儲量(19.04 Mg C/ha)。通過One-compartment模型,本研究計算出我國黃土高原地區(qū)旱地土壤有機質的礦化速率(1%)和腐殖化系數(23%)。此外,我們預測需要近22年的時間該類型土壤的有機碳庫容才能達到周轉平衡狀態(tài),說明目前土壤有機碳庫尚未達到飽和狀態(tài),還有繼續(xù)固持碳素的潛力和空間。整體來看,在黃土高原地區(qū)傳統(tǒng)的冬小麥-夏休閑體系中長期引入綠肥作物能夠有效促進冬小麥生長和養(yǎng)分吸收、提高冬小麥生產力水平和水分利用效率,并能夠替代部分冬小麥生長季的無機氮肥施用量;同時,種植豆科綠肥能夠有效降低土壤礦質氮向深層淋溶的風險,并顯著提高旱地表層土壤肥力水平。因此,在黃土高原地區(qū)發(fā)展綠肥產業(yè)體系具有一定的可行性,同時將對我國發(fā)展穩(wěn)產高效、環(huán)境友好型的現代化農業(yè)帶來深遠的影響。
[Abstract]:As a typical rainfed agriculture area, sustainable development of agriculture in the Loess Plateau of China are facing water shortage and poor soil brought challenges. During the summer fallow period and planting green manure crops can not only effectively improve soil fertility and crop growth and yield formation to promote, and can improve the nutrient in time and space aspects of water, utilization of natural resources such as heat rate, therefore, this study was carried out through the long-term test in Weibei dryland (2008 - present), different planting green manure legume research area of the Loess Plateau (Huai bean, soybean and mung bean, summer fallow and winter wheat as control) the growing season of different nitrogen levels (0108135162 kg N/ha) effects on soil water and nitrogen supply, preliminary study on effect and mechanism of coordination of leguminous green manure soil moisture and nitrogen supply, to The recovery and development of China's green industry system to provide theoretical basis and technical support of science. The main results are as follows: (1) through the field test data of 4 years, the study found that in successive years and planting leguminous green manure than the traditional bare summer leisure can effectively promote the following winter wheat seedling growth (winter the number of tillers per plant and total stem number), spring late yield (yield, biomass and spike number) and nutrient uptake. However, due to the need for additional labor cost and field management system, serious leguminous green manure higher production costs affect the system economic benefits. In addition, less nitrogen fertilizer nitrogen fertilization significantly improve dryland winter wheat growth status, yield, nutrient absorption and economic benefits, however, there was no significant difference between the three kinds of nitrogen fertilizer; (2) through 6 years of field test results when combined with Rainfall meteorological data of 57 years, a detailed analysis of the Weibei Dry land winter wheat planting characteristics of temporal and spatial distribution of rainfall area, the yield and water use efficiency of winter wheat using leguminous green manure in different rainfall years preliminary study on the condition of loess plateau area, and explore the internal mechanism of leguminous green manure in upland soil water balance and coordination for many consecutive years. Found in summer fallow period of leguminous green manure will deplete the soil moisture at the same time, the measures for different rainfall types and the yield of winter wheat stubble bring about different effects. When the rainfall is abundant, planting leguminous green manure in summer fallow period caused by soil water deficit can be added in a timely manner, Leguminosae green manure can increase the yield of Winter Wheat in dryland; on the contrary, the drought measures will bring serious production effects. Overall, during the test of planting and turning over green fertilizer than legume The summer fallow significantly increased winter wheat yield and water utilization rate, the average increase rate was 13% and 27%. respectively. At the same time, green manure on soil water balance in Dryland promotion also plays an important role; (3) with 374 days of leguminous green manure decomposition test, nitrogen and further explore the growth period of leguminous green manure accumulated in planting system of Winter Wheat in Dryland in the traditional absorption mechanism of transformation and utilization. The study found that the average annual leguminous green manure during the test in its flowering through the shoot and root biomass accumulation of total nitrogen by 53~76 kg N/ha, returning pressure over a year, at least 32 kg N/ha nitrogen mineralization after decomposition of green manure the soil microorganisms released to the surrounding environment; among them, there are about 7~27 kg N/ha was eventually after the winter wheat crop absorption and utilization. Overall, the average annual total investment of legume nitrogen 1 system 64 kg N - HA-1 - yr-1, nitrogen uptake averaged 114 kg N - HA-1 - yr-1, eventually lead to nitrogen surplus of approximately 50 kg of N - HA-1 - yr-1 system of the year in the soil. In summer fallow period application of leguminous green manure can effectively replace 13~48% (average 31%) season of inorganic nitrogen fertilizer the growth of winter wheat. In addition, 4 consecutive years of leguminous green manure in summer fallow period can reduce soil nitrate nitrogen to the deep layer (100~200 cm) leaching risk, reduce the average nitrate leaching to 19.6 kg N/ha; (4) through the field test results of 5 years, to explore the application of leguminous green manure on the Loess Plateau in China effect of dry soil carbon and nitrogen storage capacity; at the same time using the One-compartment model, the dynamic mechanism of soil organic carbon turnover fitting. Found in the Loess Plateau during summer fallow planting short bean green manure, biomass and carbon, nitrogen accumulation and growth cycle A very significant power function relationship. After a year of decomposition of carbon mineralization, average shoot and root soil in dryland wheat, the residual rate of legumes were 26% and 33%; and the average nitrogen corresponding residual rate was 31% compared with 52%. and foundation soil samples in summer fallow period and planting pressure over consecutive years leguminous green manure significantly improve dryland wheat, soil organic carbon, labile organic carbon and total nitrogen content and storage reserves accordingly. In addition, there is a significant positive correlation between the test surface fifth years reserves of soil organic carbon pool and the average annual crop carbon residue amount, organic carbon storage and annual crop carbon returning amount of at least 0.68 Mg C HA-1 yr-1 can maintain the basic foundation soil (19.04 Mg C/ha). Through the One-compartment model, this study calculates the mineralization rate in China Loess Plateau Dryland Soil organic matter (1%) and rot Colonization factor (23%). In addition, we predict the need for nearly 22 years the soil organic carbon storage in order to achieve turnover equilibrium, the soil organic carbon library has not yet reached saturation, and continue holding carbon potential and space. Overall, the introduction of long-term green manure crops can effectively promote the growth and nutrition of winter absorption of wheat in the Winter Wheat Yellow Soil Plateau traditional summer fallow system, improve Winter Wheat Productivity and water use efficiency, and can replace part of winter wheat growing season of inorganic nitrogen; at the same time, the risk of leguminous green manure can effectively reduce soil mineral nitrogen to deep leaching, and significantly improve the fertility level of the surface Dryland Soil in the Loess Plateau region. Therefore, the development of green industry system has certain feasibility, while the stable development of our country's modern efficient, environment friendly Agriculture has a far-reaching impact.

【學位授予單位】：西北農林科技大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：S55;S512.11
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本文編號：1628977