Details

Autor(en) / Beteiligte

• Sharma, K.L.
• Mandal, Uttam Kumar
• Srinivas, K.
• Vittal, K.P.R.
• Mandal, Biswapati
• Grace, J. Kusuma
• Ramesh, V.

Titel

Long-term soil management effects on crop yields and soil quality in a dryland Alfisol

Ist Teil von

• Soil & tillage research, 2005-09, Vol.83 (2), p.246-259

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2005

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A long-term experiment was conducted with the objective of selecting the appropriate land management treatments and to identify the key indicators of soil quality for dryland semi-arid tropical Alfisols. The experiment was conducted using a strip split–split plot design on an Alfisol (Typic Haplustalf) in southern India under sorghum ( Sorghum vulgare (L))-castor ( Ricinus communis (L)) bean rotation. The strip constituted two tillage treatments: conventional tillage (CT) and minimum tillage (MT); main plots were three residues treatments: sorghum stover (SS), gliricidia loppings (GL), ‘no’ residue (NR) and sub plots were four nitrogen levels: 0 (N 0), 30 (N 30), 60 (N 60), and 90 kg ha −1 (N 90). Soil samples were collected after the sixth and seventh year of experimentation and were analyzed for physical, chemical and biological parameters. Sustainable yield index (SYI) based on long-term yield data and soil quality index (SQI) using principal component analysis (PCA) and linear scoring functions were calculated. Application of gliricidia loppings proved superior to sorghum stover and no residue treatments in maintaining higher SQI values. Further, increasing N levels also helped in maintaining higher SQI. Among the 24 treatments, the SQI ranged from 0.90 to 1.27. The highest SQI was obtained in CTGLN 90 (1.27) followed by CTGLN 60 (1.19) and MTSSN 90 (1.18), while the lowest was under MTNRN 30 (0.90) followed by MTNRN 0 (0.94), indicating relatively less aggradative effects. The application of 90 kg N ha −1 under minimum tillage even without applying any residue (MTNRN 90) proved quite effective in maintaining soil quality index as high as 1.10. The key indicators, which contributed considerably towards SQI, were available N, K, S, microbial biomass carbon (MBC) and hydraulic conductivity (HC). On average, the order of relative contribution of these indicators towards SQI was: available N (32%), MBC (31%), available K (17%), HC (16%), and S (4%). Among the various treatments, CTGLN 90 not only had the highest SQI, but also the most promising from the viewpoint of sustainability, maintaining higher average yield levels under sorghum–castor rotation. From the view point of SYI, CT approach remained superior to MT. To maintain the yield as well as soil quality in Alfisols, primary tillage along with organic residue and nitrogen application are needed.