تاثير تراكم ، رطوبت و كود دامي بر ذخاير كربن و ويژگي هاي ساختماني خاك هاي مختلف تحت كشت ذرت

چكيده انگليسي :

Compaction Moisture and Farmyard Manure Effects on Carbon Sources and Structural Characteristics of Different Soils under Corn Cultivation Mahsa Rahimi Naini Mahsarahimi59@yahoo com 1389 10 29 Department of Soil Science Isfahan University of Technology 84156 83111 Iran Degree M Sc Language Farsi M A Hajabbasi hajabbas@cc iut ac ir Abstract Increase in earth surface temperature and the outcomes take attention of scientists to find out thereasons Green house gases especially carbon dioxide in atmosphere are known as the main reasons forthis phenomena Sources of carbon in agricultural soils are important factors in the global carbon cycle These sources are in contact with atmosphere and act as a tool to control its carbon dioxide The emissionof carbon dioxide to atmosphere can be decreased with increase in carbon sources in soils Increase inearth surface temperature and the outcomes take attention of scientists to find out the reasons Greenhouse gases especially carbon dioxide in atmosphere are known as the main reasons for this phenomena Sources of carbon in agricultural soils are important factors in the global carbon cycle These sources arein contact with atmosphere and act as a tool to control its carbon dioxide The emission of carbon dioxideto atmosphere can be decreased with increase in carbon sources in soils Soil carbon sequestrationimproves soil quality and limits the proportion of carbon dioxide emission of agricultural land to theatmosphere Labile organic matter pools can be considered as fine indicators of soil quality that are verysensitive to changes in soil management practices This research is conducted to evaluate the effects ofcompaction moisture and farmyard manure on carbon sources soils The structural characteristics of fourdifferent textured soils under corn cultivation in Isfahan University of Technology research green houseswere also evaluated Eight treatments with three replications in four soil texture sandy loam loam clayloam and silty clay are considered Compaction treatment with 2 relative compaction levels of 0 83 and0 91 moisture 70 and 90 percent of FC level and farmyard manure with zero and 25 ton per hectare levelswere used Corn single cross cultivar was planted and after three months plant and soil characteristicswere analyzed Organic matter particulate organic matter POM acid hydrolysable carbohydrate AHC and mean weight diameter MWD were measured in soils Results show that adding farmyard manure tothe soil increased POM in all soil textures In addition farmyard manure in fine and coarse textureincreased the organic matter and AHC Aggregate stability was increased by adding manure in all texturesexcept for the silty clay texture Soil POM was increased in coarse textures loam and sandy loam byincreasing moisture Aggregate stability was increased in soils with coarse texture sandy loam and loam by increasing moisture However in fine texture higher moisture content caused a reduction in aggregatestability In addition increasing in relative compaction in coarse texture loam and sandy loam causeddecline in aggregate stability but in the fine texture silty clay and clay loam a positive effect of relativecompaction was seen for aggregate stability increased Increasing in compaction influenced carbohydratesonly in sandy loam and silty loam textures In coarse texture increase the relative compaction caused instatistically increases in carbohydrate but in fine texture the effect was negative Soil organic mattercontent decreased in loam and silty clay texture by increasing in compaction Furthermore increasingrelative compaction in silty clay as a fine texture soil increase the amount of POM Key words compaction particle organic matter POM acid hydrolysablecarbohydrate AHC aggregate stability

رحيمي نائيني، مهسا

تاثير تراكم ، رطوبت و كود دامي بر ذخاير كربن و ويژگي هاي ساختماني خاك هاي مختلف تحت كشت ذرت

ماده آلي ذره اي , كربوهيدرات , پايداري خاكدانه