By comparing micromorphological features of irrigated and non-irrigated soils in Guanzhong areas, China, this paper tries to illustrate the influences of farming management methods on the soil-forming process. The mic...By comparing micromorphological features of irrigated and non-irrigated soils in Guanzhong areas, China, this paper tries to illustrate the influences of farming management methods on the soil-forming process. The micromorphology was observed under a petrographic microscope and its image was quantificationally measured by Nikon NISBR 2.2 software. Both irrigated and non-irrigated soils have the same soil profile pattern, Ap1- AP2- BC, but the former has a more obvious profile dissimilation. The minerals assemblage of soil profiles A and B are very similar, which is mainly composed of Q and P1. Compared with non-irrigated soil, grains of irrigated soil remarkably decrease in length, area, eqdiameter, perimeter, elongation, roundness, and C/F10μm ratio; voids are characterized by more regular void shape and more smooth void wall; there is more abundant residual clay and small amount of illuvial clay. All results in this study suggest that the farming management method has influences on soil profile dissimilation and micromorphology. Agricultural irrigation could strengthen the degree of weathering, make smaller and rounder soil grains, cause a significant increase of residual clay and appearance of illuvial clay. But no significant change has been observed in the minerals assemblage of coarse grains.展开更多
为建立关中灌区冬小麦施肥指标体系,对关中灌区2008年95个冬小麦"3414"大田试验数据进行整理、分析,以相对产量70%、80%、90%和95%划分土壤养分丰缺指标,并利用一元二次模型对各试验点施肥量与产量关系进行模拟,确定各试验点...为建立关中灌区冬小麦施肥指标体系,对关中灌区2008年95个冬小麦"3414"大田试验数据进行整理、分析,以相对产量70%、80%、90%和95%划分土壤养分丰缺指标,并利用一元二次模型对各试验点施肥量与产量关系进行模拟,确定各试验点最佳经济产量施肥量,最终建立了关中灌区冬小麦基于土壤碱解氮(AN)、有效磷(AP)和速效钾(AK)测定值的氮、磷、钾推荐施肥模型,确定了不同肥力水平下的推荐施肥量:当碱解氮含量处于极低(<50 mg kg-1)、低(50～80 mg kg-1)、中(80～120 mg kg-1)和高等级(>120 mg kg-1)时,氮肥(N)施用量分别为190～230 kg hm-2、150～190 kg hm-2、110～150 kg hm-2和0～110 kg hm-2;有效磷含量处于极低(<10 mg kg-1)、低(10～20 mg kg-1)、中(20～35 mg kg-1)和高等级(>35 mg kg-1)时,磷肥(P2O5)施用量分别为130～160 kg hm-2、110～130 kg hm-2、90～110 kg hm-2和0～90 kg hm-2;速效钾含量处于低(<90 mg kg-1)、中(90～150 mg kg-1)、高(150～190 mg kg-1)和极高等级(>190 mg kg-1)时,钾肥(K2O)施用量分别为120～150 kg hm-2、90～120 kg hm-2、70～90 kg hm-2和0～70 kg hm-2。示范试验证明推荐施肥处理较农民习惯施肥处理平均增产789 kg hm-2,增收1 227元hm-2,肥料贡献率提高8.2个百分点,每kg氮磷钾肥小麦增产量提高1.7 kg。展开更多
基金This research was financially supported by the National Natural Science Foundation of China （40471119, 40571154） Project of State Key Laboratory of Loess and Quaternary Geology of China （SKLLQG0604） Natural Science Foundation of Shaanxi Province （2006D01）.
文摘By comparing micromorphological features of irrigated and non-irrigated soils in Guanzhong areas, China, this paper tries to illustrate the influences of farming management methods on the soil-forming process. The micromorphology was observed under a petrographic microscope and its image was quantificationally measured by Nikon NISBR 2.2 software. Both irrigated and non-irrigated soils have the same soil profile pattern, Ap1- AP2- BC, but the former has a more obvious profile dissimilation. The minerals assemblage of soil profiles A and B are very similar, which is mainly composed of Q and P1. Compared with non-irrigated soil, grains of irrigated soil remarkably decrease in length, area, eqdiameter, perimeter, elongation, roundness, and C/F10μm ratio; voids are characterized by more regular void shape and more smooth void wall; there is more abundant residual clay and small amount of illuvial clay. All results in this study suggest that the farming management method has influences on soil profile dissimilation and micromorphology. Agricultural irrigation could strengthen the degree of weathering, make smaller and rounder soil grains, cause a significant increase of residual clay and appearance of illuvial clay. But no significant change has been observed in the minerals assemblage of coarse grains.
文摘为建立关中灌区冬小麦施肥指标体系,对关中灌区2008年95个冬小麦"3414"大田试验数据进行整理、分析,以相对产量70%、80%、90%和95%划分土壤养分丰缺指标,并利用一元二次模型对各试验点施肥量与产量关系进行模拟,确定各试验点最佳经济产量施肥量,最终建立了关中灌区冬小麦基于土壤碱解氮(AN)、有效磷(AP)和速效钾(AK)测定值的氮、磷、钾推荐施肥模型,确定了不同肥力水平下的推荐施肥量:当碱解氮含量处于极低(<50 mg kg-1)、低(50～80 mg kg-1)、中(80～120 mg kg-1)和高等级(>120 mg kg-1)时,氮肥(N)施用量分别为190～230 kg hm-2、150～190 kg hm-2、110～150 kg hm-2和0～110 kg hm-2;有效磷含量处于极低(<10 mg kg-1)、低(10～20 mg kg-1)、中(20～35 mg kg-1)和高等级(>35 mg kg-1)时,磷肥(P2O5)施用量分别为130～160 kg hm-2、110～130 kg hm-2、90～110 kg hm-2和0～90 kg hm-2;速效钾含量处于低(<90 mg kg-1)、中(90～150 mg kg-1)、高(150～190 mg kg-1)和极高等级(>190 mg kg-1)时,钾肥(K2O)施用量分别为120～150 kg hm-2、90～120 kg hm-2、70～90 kg hm-2和0～70 kg hm-2。示范试验证明推荐施肥处理较农民习惯施肥处理平均增产789 kg hm-2,增收1 227元hm-2,肥料贡献率提高8.2个百分点,每kg氮磷钾肥小麦增产量提高1.7 kg。
