Sustaining soil health and cotton productivity with tillage and integrated nutrient management in Vertisols of Central India

Abstract

In order to assess soil health and cotton productivity as a means of tillage and integrated nutrient management (INM) practices, the experiment was conducted at Department of Soil Science and Agricultural Chemistry, Dr Panjabrao Deshmukh Krishi Vidyapeeth, Akola (Maharashtra) during 2010−11 to 2015−16 in split plot design with two sets of main plots namely, minimum and conventional tillage replicated thrice. The treatments (8 sub−plots) comprised of 100% recommended dose of fertilizer (RDF), 50% RDF + in−situ green manuring with sunhemp, 50% N through FYM + RDF compensation through chemical fertilizers, 50% N through wheat straw (WS) + RDF compensation through chemical fertilizers, 50% N through gliricidia green leaf manuring (GLM) + RDF compensation through chemical fertilizers, 25% N through FYM + 25% N through WS + remaining recommended dose (RD) through chemical fertilizers, 25% N through FYM + 25% N through GLM + remaining RD through chemical fertilizers and 25% N through WS + 25% N through GLM + remaining RD through chemical fertilizers. The minimum tillage included one harrowing and two hand weedings, while conventional tillage included one ploughing, one harrowing, two hoeing and two hand weedings. The results of the present study indicated that, minimum tillage practice found promising for obtaining higher seed cotton (1.25 t ha−1) and cotton stalk (2.92 t ha−1) yield over conventional tillage. Among various resource management practices, the application of 50% N through FYM + RDF compensation through chemical fertilizers significantly (p<0.05) increased the seed cotton (1.35 t ha−1) and cotton stalk (3.18 t ha−1) yield. The sustainable yield index (0.71) and soil quality index (SQI) (2.29) was higher with combined use of manures and fertilizers than 100% RDF. The adoption of minimum tillage improved hydraulic conductivity (0.72 cm hr−1), mean weight diameter (0.70 mm), organic carbon (OC) (5.86 g kg−1), available N status (225 kg ha−1), soil microbial biomass nitrogen (SMBN) (43.77 mg kg−1), SMBC (248 mg kg−1) and dehydrogenase activity (DHA) (50.83 μg g−1 24 hr−1). The improvement in soil physical [bulk density (BD), hydraulic conductivity and mean weight diameter], chemical [pH, electrical conductivity (EC), OC], soil fertility status [available N, P and K] and biological properties (SMBC, SMBN and DHA) was noticed in 50% N through FYM + RDF compensation through chemical fertilizers, the same treatment was exhibited in obtaining higher SOC stock (16.13 Mg ha−1). There exists a significant relationship among soil organic carbon (SOC) stock (R2 = 0.637**) and SQI (R2 = 0.915**) with SYI. Thus, it can concluded that, adoption of minimum tillage practice in conjunction with resource management practices (50% N through FYM + RDF compensation through chemical fertilizers) helps in sustaining cotton productivity and soil quality. Adoption of minimum tillage with 50% N through gliricidia GLM and compensation of RDF through chemical fertilizers helps in getting higher net returns and B:C ratio.