為了揭示黑土侵蝕對作物生產(chǎn)力的影響及其響應機制，中科院東北地理與農(nóng)業(yè)生態(tài)研究所農(nóng)田分子生態(tài)學科組苗淑杰副研究員等基于人為剝離表層黑土及其修復的長期定位試驗（2005年在海倫市建立）,，在初步證實土壤侵蝕降低玉米大豆產(chǎn)量,，而牛糞肥提升作物生產(chǎn)力的基礎上，選擇了長期試驗中的3個模擬侵蝕水平,，即表土剝離0,、10和30cm，結(jié)合兩個土壤修復方法：一是按照當?shù)剞r(nóng)民施肥習慣僅施用化肥,，二是在化肥的基礎上施用1,，5000kg ha-1(以干重計)牛糞肥,，分析了長期施用牛糞肥對玉米和大豆田土壤中低分子量有機酸的影響。
結(jié)果表明,，與單施化肥處理相比,，7年連續(xù)施用牛糞肥顯著增加了根際和非根際土壤中主要低分子量有機酸總量，其中,，根際土壤中增加了9-70倍,，非根際土壤增加了6-62倍。玉米區(qū)和大豆區(qū)土壤中各主要低分子量有機酸增加的程度不同,，玉米區(qū)低分子量有機酸增加的趨勢表現(xiàn)為草酸>蘋果酸>丙二酸>乳酸>馬來酸,，大豆區(qū)表現(xiàn)為草酸>蘋果酸>馬來酸>乳酸。比較而言,，施用牛糞肥和表土剝離對玉米區(qū)土壤低分子量有機酸含量的影響強于大豆區(qū),。此外，研究還發(fā)現(xiàn)表土剝離和連續(xù)七年施用牛糞肥對土壤溶液中主要低分子量有機酸含量的影響機制不同,，兩者無直接聯(lián)系,。
上述研究結(jié)果表明，通過施用牛糞肥增加土壤中低分子量有機酸來調(diào)整土壤生物學特性是修復中國侵蝕黑土的一項有效措施,。（生物谷Bioon.com）
生物谷推薦的英文摘要
Plant and Soil DOI:10.1007/s11104-013-1594-3
Seven years of repeated cattle manure addition to eroded Chinese Mollisols increase low-molecular-weight organic acids in soil solution
Shu-jie Miao,， Hai Shi， Guang-hua Wang,， Jian Jin,， Ju-dong Liu，Ke-qin Zhou,， Yu-yue Sui,， Xiao-bing Liu
Background and aims
Organic amendments are an option in enhancing soil biological productivity. Limited research exists on the effects of long-term cattle manure addition on low-molecular-weight organic acids (LMWOAs) concentrations in corn (Zea mays L) and soybean (Glycine max L.) fields in the region of soil erosion. The purpose of this study was to investigate the potential influence of cattle manure on the LMWOAs concentration in erosion soil.
Methods
A field experiment was established in Hailun city， Northeast China to determine the impact of long-term cattle manure addition on the total amounts of main LMWOAs in eroded Mollisol fields. There were three levels of simulated-erosion,， which removed 0,， 10 and 30 cm of topsoil. Two soil amendments were： (1) chemical fertilizer at the rate normally used by farmers in the region and (2) chemical fertilizer plus 15，000 kg,？ha,？1 (dry weight basis) of cattle manure. Main LMWOAs in soil were assessed at the flowering stage of soybean and the jointing stage of corn.
Principle results
Compared to chemical fertilizer alone， 7-years of repeated cattle manure addition significantly increased total amounts of main LMWOAs in rhizosphere about 9–70 times and bulk soil about 6–62 times. The magnitude of increase by cattle manure was in the order of oxalate>malate>malonate>lactate>maleate in corn plots,， and oxalate>malate>malonate>lactate in soybean plots. In comparison,， cattle manure and topsoil removal had larger effect on LMWOAs concentrations in corn plot than soybean plot. The addition of cattle manure application and top soil removal had significant independent influence on main LMWOAs concentration in soil solution.
Conclusion
This study suggested that addition of cattle manure would be an effective approach in modifying soil biological properties through the increases in low-molecular-weight organic acids to eroded Chinese Mollisols.
