淮北砂姜黑土微生态环境及作物光合对长期不同施肥模式的响应

The lime concretion black soil in Huaibei area of Anhui province exists the adverse property of “drought, waterlogging, concretion, leanness”, in order to explore an effective soil fertilization model for this area in which the basic soil fertility and crop yield are low, the present study relies on long-term located fertilization experiment with 33 years, mainly research the effects of different long-term fertilization models on micro-ecological environment，crop photosynthesis and yield in lime concretion black soil of Huaibei area, the aims on the one hand to reveal the effects of different long-term fertilization models on the results of long-term evolution of microbial quantity and enzyme activities in lime concretion black soil and on the potential mechanism of crop photosynthetic rate, chlorophyll fluorescence and yield, on the other hand to clarify the relationship between soil microbial quantity and enzyme activities, and the relationship among soil micro-ecological environment and crop photosynthesis, yield. Screen out an effective soil fertilization model that is suitable for lime concretion black soil in Huaibei area of Anhui province, so as to provide the scientific basis and theoretical guidance for cultivating soil fertility, using soil sustainably and establishing long-term and regional fertilization plan in lime concretion black soil area, to improve local soil micro-ecological environment to a certain extent, and create good soil conditions for crop production. The completion of this research project has a certain pushing effect and theoretical guidance significance on enhancing soil quality and crop yields in lime concretion black soil area, and on achieving a win-win situation of efficient agricultural production and ecological environment.

安徽淮北砂姜黑土存在着“旱、涝、僵、瘦”的不良属性，为探索出针对该区土壤基础肥力薄弱和作物产量低下的有效土壤培肥模式，本研究依托33年长期定位施肥试验，重点探讨长期不同施肥模式对淮北砂姜黑土微生态环境及作物光合效应和产量的影响，一方面揭示长期不同施肥模式对砂姜黑土微生物数量和酶活性长期演变结果及作物光合速率、叶绿素荧光和产量影响的潜在机理，另一方面阐明土壤微生物数量和酶活性间的关系及土壤微生态环境与作物光合、产量间的关系。筛选出适宜于安徽淮北砂姜黑土的有效土壤培肥模式，为砂姜黑土区土壤肥力培育、土壤可持续利用及长远性、区域性施肥规划的建立提供科学依据和理论指导，进而在一定程度上改善该区土壤微生态环境，为作物生产创造良好的土壤条件。该项目的完成对提高砂姜黑土区土壤质量和作物产量，实现农业高效生产与生态环境的共赢具有一定的推动作用和理论指导意义。

砂姜黑土养分贫瘠、保水保肥性能差，致使作物增产困难。为此依托长期定位试验研究了5种不同施肥模式不施肥CK、单施化肥NPK、单施有机肥M、有机肥与化肥配施MNPK（等氮）和HMNPK（高氮）对砂姜黑土小麦玉米产量、光合特性、根系及根际土壤微生物数量和酶活性的影响，以筛选出该区土壤有效培肥模式，并揭示各培肥模式效果间差异的机理。. 研究发现①有机肥与化肥配施相对于长期单施化肥和有机肥能明显提高土壤细菌、真菌、放线菌、硝化细菌、氨化细菌、溶磷菌数量及土壤转化酶、脱氢酶、磷酸酶、蛋白酶、脲酶、过氧化氢酶、硝酸还原酶活性；②M在增加土壤微生物数量和酶活性方面的总体效果优于NPK，并可显著增加土壤真菌和固氮菌数量；③有机肥与化肥配施下增加施氮量对土壤微生物数量、酶活性及微生物量碳氮改善不明显，且会抑制固氮菌数量和过氧化氢酶活性的增加；④土壤酶活性和微生物数量间存在正相关关系，增加微生物数量对提高酶活性具有重要作用；⑤长期有机肥与化肥配施相对于长期单施化肥和有机肥可显著增加小麦总根长、根表面积、根体积、根尖数及冠层光合高效叶片长宽；⑥在提高玉米和小麦叶绿素含量、叶面积及改善叶片光合特性和叶绿素素荧光参数方面有机肥与化肥配施优于单施化肥和有机肥，单施有机肥优于单施化肥；⑦M玉米产量相比NPK显著增加6.0％以上，有机肥与化肥配施可显著增加玉米产量，但施氮量偏高对玉米产量及其构成改善不明显，且特殊年份易造成小麦倒伏减产；⑧不施肥下（小麦盆栽试验），M每盆经济产量和生物产量、收获指数分别比NPK显著增加10.6％、7.6％、3.0％，MNPK和HMNPK每盆经济产量和生物产量比NPK显著增加26.3％、15.9％和20.6％、14.0％。. 研究证实在改善作物光合、产量及培肥土壤基础肥力和养分后续供应能力方面，有机肥与化肥配施优于单施有机肥和化肥，单施有机肥优于单施化肥，且有机肥与化肥配施下施氮量不宜偏高。本研究为砂姜黑土改良及实现养分低投入产量高产出的目标提供了一定科学依据和理论帮助。