5th
17
Uzun
alitesi
1* 2 Mert Acar1 Nurullah Acir3 Zeliha Bereket Barut4
1 2 3 4
- -soya fasulyesi rotasyonundaki Vertisol bir 1), Rototillerli -10 cm derinlikteki toprak organik karbo -PMN -- -- -uy
Anahtar Kelimeler: Toprak Glikosidaz, Organik Karbon,
Effects of Long-Term Soil Tillage and Crop Rotation on Soil Biological Quality*
Abstract
The most sensitive indicator of changes in land use or management is biological soil quality (BSQ). This study was carried out to investigate the effects of soil tillage systems on BSQ. The experiment has been continuing for nine years under Cukurova conditions in a Vertisol soil with corn-wheat-soybean rotation. Six tillage treatments of the experiment are: Conventional tillage with stubble (CT-1), Conventional tillage with stubbles burned (CT-2), Heavy disc harrow reduced tillage (RT-1), Rototiller reduced tillage (RT-2), Heavy disc harrow zero soil tillage (HZT), no-till (ZT) treatment. The experiment was established in 2006 at Experimental and Research Station of Cukurova University with 3 replicates according to complete randomized block experimental design. Soil organic carbon (SOC), potentially mineralizable nitrogen (PMN), microbial biomass carbon (MBC) and beta glucosidase enzyme activity (GEA) were determined for 0-10 cm soil depth sampled from experimental plots. The data were converted to unitless scores using non-linear scoring curves of soil management assessment framework developed by United States Department of Agriculture. Each of the four BSQ indicators significantly (P 0.01) with the change of the soil tillage system. The highest MBC, GEA and SOC indicator scores were obtained under NT. PMN under RT-1 (0.86) and NT (0.82) were found relatively higher compared to other treatments. In particular, the GEA indicator score was 0.72 under the NT system and significantly decreased under the CT-1 (0.06) and CT-2 (0.06) treatments. BSQ scores varied between 51.3% (CT-1) and 86.8% (NT) due to the significant differentiation of MBC, PMN, GEA and SOC indicators. The average BSQ score under NT treatment was 69% and 58% higher than the CT-1 and CT-2 treatments performed by the use of plough. Under the NT treatment, continuous addition of biomass carbon through crop residue to the soil surface resulted in higher biological quality of soil.
Key Words: Soil Health, Potentially Mineralizable Nitrogen, Beta Glucosidase, Organic Carbon, Microbial Biomass Carbon
