【作者】 李志军；

【导师】 张树兰；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2010， 硕士

【摘要】 本文以关中灌区小麦-玉米轮作体系下18年和28年的长期肥料定位试验为基础,探讨了长期不同施肥管理下塿土中微量元素的有效含量,小麦和玉米苗期地上部、灌浆期功能叶片以及收获后秸秆和籽粒中微量元素铁(Fe)、锰(Mn)、铜(Cu)和锌(Zn)的营养状况。18年定位施肥管理措施包括不施肥(CK),氮磷钾肥(NPK),玉米季秸秆还田配合氮磷钾(SNPK)以及有机肥配合氮磷钾(MNPK),共4种施肥方式;28年定位施肥管理包括不施肥(CK),氮磷肥(NP),有机肥(M),有机肥配合氮磷肥(MN1P1,MN2P2),共5种施肥方式。本文取得的主要研究成果如下:1、18年和28年不同定位施肥管理对耕层土壤有效Fe、Mn、Cu和Zn的含量有显著的影响。CK处理土壤有效铁,锰,铜和锌含量均处于亏缺边缘值范围;NP处理土壤有效Fe、Cu和Zn含量接近亏缺边缘值;NPK处理土壤有效铁,锰,锌含量也接近亏缺边缘值的上限。而M,SNPK和MNP或MNPK处理土壤有效铁,锰,铜和锌含量较高。从剖面分布变化来看,各微量元素的含量(除Cu外)均随土层深度增加而降低。M,MNP和MNPK较CK处理均显著增加0-10cm土层有效Fe、Mn、Cu和Zn的含量,也有增加10cm以下土层土壤有效Fe、Mn、Cu和Zn含量的趋势,其中MNPK显著增加了Fe在整个剖面的含量;NP和NPK较CK处理也增加0-10cm土层土壤有效Fe和有效Mn的含量,而对有效Cu和有效Zn含量没有明显影响,10cm以下各土层土壤有效Fe、Mn、Cu和Zn含量与CK处理相似。2、28年定位施用NP,M或MNP较CK均在不同程度上降低小麦、玉米苗期地上部Fe和Zn的含量,但是所有处理作物Fe、Mn、Cu和Zn含量均在适宜含量范围。M和MNP处理小麦旗叶和倒二叶的Cu含量均低于临界浓度,而NP和CK处理Cu的含量高于临界浓度。而所有处理小麦旗叶和倒二叶均显示缺Zn,长期施用NP,M或MNP玉米棒下叶也缺Zn。长期施肥(NP,M或MNP)较不施肥降低小麦籽粒中Fe、Cu和Zn的含量,玉米Zn的含量(除MN2P2外)。综合本试验小麦-玉米轮作体系下不同处理微量元素的效应,以M2N2P2处理最好。3、18年不同定位施肥影响小麦和玉米苗期植株的Fe、Mn、Cu和Zn营养状况,其中Fe、Mn和Cu含量均在适宜的含量范围。但是,长期施用NPK化肥小麦苗期地上部缺Zn,并且除CK处理外其他施肥处理玉米也均表现缺Zn。灌浆期与苗期相似,小麦旗叶或玉米棒下叶Fe、Mn和Cu含量均在适宜的含量范围,但是小麦旗叶和倒二叶、玉米棒下叶Zn的含量均处于临界浓度值以下。由此也导致小麦和玉米籽粒的Zn含量较低,尤其是施肥处理。表观平衡分析表明长期施用NPK化肥土壤Fe有盈余,Mn、Cu和Zn表现为净消耗;一季作物秸秆还田配合氮磷钾土壤Fe、Mn和Cu均有盈余,而Zn仍然亏缺;有机肥配合氮磷钾土壤各个元素均有盈余。综合以上结果,塿土在不施用有机肥的情况下,建议施用微肥以避免作物的铁和锌的亏缺。在一季秸秆还田配合化肥的情况下建议补充锌肥。有机肥或有机肥和化肥配合施用尽管显著提高土壤4种微量元素的有效含量,但是小麦仍出现缺铜和缺锌以及玉米缺锌的状况,如何优化耦合有机-无机肥,改善作物微量元素的营养状况仍然需要进一步探讨。更多还原

【Abstract】 The effects of fertilizer management regimes on status of iron, manganese, copper and zinc in soil and crops were investigated based on the 18-year and 28-year long-term experiments on Lou soil in Guanzhong Plain, Shaanxi province, China. The 18-year fertilizer management regimes included: (1) control without appling any fertilizer (CK), (2) application of chemical nitrogen(N), phosphorus(P) and potassium(K) fertilizers (NPK), (3) application of NPK chemical fertilizers plus corn stalk (SNPK) and (4) application of NPK chemical fertilizers plus dairy manure (MNPK). The 28-year fertilizer management regimes included (1) control without appling any fertilizer (CK), (2) application of organic manure (M2), (3) application of chemical nitrogen and phosphorus fertilizers (N2P2), (4) application of nitrogen and phosphorus chemical fertilizers plus dairy manure (M2N1P1 and M2N2P2). The main results obtained were as follows:1. Soil available iron, manganese, copper and zinc contents in ploughed layer (0-20 cm) were significantly affected by fertilizer management regimes. It showed that the contents of soil available Fe, Mn, Cu and Zn under CK, Fe, Cu and Zn under NP and Fe, Mn and Zn under NPK were close to be deficient. While on M, SNPK, MNPK and MNP treatments, above trace elements were in abundance. In term of the spatial variation in the soil profile, compared to CK, application of SNPK, M, MNP and MNPK can significantly increase the contents of iron, manganese, zinc, copper at 0-10cm layer and also had the tendency to increase at layers below 10 cm. Application of chemical fertilizers (NP and NPK) also increased available contents of Fe and Mn, and had no effect on soil available Cu and Zn at 0-10cm layer, soil available Fe, Mn, Cu and Zn at deeper layers were similar between treatments.2. Compared to CK, the contents of iron and zinc in wheat and maize seedlings were more or less reduced under 28-year application of NP, M and MNP, but in all treatments, the contents of iron, manganese, copper and zinc in crops were in the rational range. The contents of copper in wheat flag leaf and the one below under M and MNP were lower than the critical concentration. The contents of zinc in wheat flag leaf and the one below in all treatments were also below the critical concentration, as well as in cob leaf of maize under NP,M and MNP. The contents of iron, zinc, copper in wheat and maize grain were decreased in fertilized treatments except under M2N2P2 relative to CK treatment. Based on above results, M2N2P2 was the best one among the tested fertilizer management regimes for wheat-maize rotation system.3. The contents of iron, manganese, zinc and copper in wheat and maize seedlings were affected by 18-year different fertilizer management regimes. The contents of iron, manganese and copper in seedlings were in the rational range, except Zn in wheat seedlings under NPK, and in maize seedlings under NPK, SNPK and MNPK, which was in deficient. Similar to seedling stage, the contents of iron, manganese and copper in wheat flag leaf and the one below and cob leaf of maize in all treatments were in abundance. However, the contents of zinc in those leaves showed Zn deficiency. As a result, the contents of zinc in wheat and maize grain were also low, especially in fertilized treatments. The apparent balance sheet indicated that input of manganese, copper and zinc did not compensate the uptake by wheat and maize, which led to depletion of those elements under NPK, except for iron; the input of iron, manganese and copper were higher than the output by crops under SNPK, except zinc which gave the negative budget value. On MNPK treatment, all four elements showed positive budget values.. Based on soil analysis and crop micronutrients’status, we suggested that micronutrient, such as Zn, should be applied in wheat-maize cropping system when chemical fertilizers and/or combination with crop straw/stalk applied. Although organic manure combined with chemical fertilizers did significantly increased levels of soil micronutrients, Cu in wheat and Zn in maize were still in deficiency. Therefore, it needs further study to optimize combination of organic manure and chemical fertilizers to improve crop’s micronutrient status.更多还原