Effect of post‐methanation effluent on soil physical properties under a soybean‐wheat system in a Vertisol

Abstract

SummaryPost-methanation effluent (PME) generated through biomethanation of distillery effluent, a foul-smelling, dark colored by-product of distillery industries, is applied to arable land in some areas near the vicinity of the distillery industries as an amendment. The PME contains considerable amount of organic matter and salt besides its high plant-nutrient content. The present investigation was conducted for three years during 1999±2002 on soybean-wheat cropping sequence to evaluate the effect of graded levels of post-methanation effluent (PME) on soil physical properties and crop productivity in a deep Vertisol of central India. Six application doses of PME viz. S 2.5 +W 0 : 2.5 cm PME applied to soybean and wheat on residual nutrition, S 2.5 +W 1.25 : 2.5 cm PME to soybean and 1.25 cm to wheat, S 5.0 +W 0 : 5 cm PME to soybean and wheat on residual nutrition, S 5.0 +W 2.5 : 5.0 cm PME to soybean and 2.5 cm to wheat, S 10.0 +W 0 : 10 cm PME to soybean and wheat on residual nutrition, and S 10.0 +W 5.0 : 10.0 cm PME to soybean and 5.0 cm to wheat, were compared with 100% recommended NPK+FYM @ 4 Mg ha ±1 and control (no fertilizer, manure or PME). The application of PME increased the organic carbon content and electrical conductivity of the soil compared to control and 100% NPK+FYM treatment. The organic C content was maximum in S 10.0 +W 5.0 (11.2 g kg ±1 ) and minimum in control (5.2 g kg ±1 ). Electrical conductivity increased from 0.47 dS m ±1 in control to 1.58 dS m ±1 in highest dose of PME (S 10.0 +W 5.0 ). The PME treatments have not affected the soil pH. The application of PME showed a significant improvement in the physical properties of the soil. The mean weight diameter (MWD), percent water-stable aggregation (% WSA), saturated hydraulic conductivity (K sat ), and water retention (WR) at 0.033 MPa suction were significantly (P < 0.05) more while bulk density (BD) and penetration resistance was significantly less in PME-treated plots than that of control. The MWD showed a linear and positive relationship (r = 0.89**) with the soil organic C. Soybean recorded significantly higher seed yield at all PME treatments than control. Highest average soybean yield (2.39 Mg ha ±1 ) was recorded in S 10.0 +W 0 but yield decreased significantly in S 10.0 +W 5.0 (2.08 Mg ha ±1 ). In wheat, all the PME-treated plots except S 2.5 +W 0 yielded significantly higher than control while the 100% NPK+FYM treatment yielded (3.46 Mg ha ±1 ) at par with the S 10.0 +W 5.0 (4.0 Mg ha ±1 ) and S 5.0 +W 2.5 (3.66 Mg ha ±1 ). Fresh application of PME to wheat resulted in significant improvement in grain yield over that grown on residual fertility. Thus, application of PME to arable land, as an amendment, could be considered as a viable option for the safe disposal of this industrial waste.

Impact of Sugar Industrial Treated Effluent on the Growth Factor in Sugarcane—Cuddalore, India

“…Similar findings were also reported by [15], in green leafy vegetables. Delayed growth reported during the primary stage of the sugarcane sapling was agreed in the previous studies [16]. [17] reported that higher concentration of effluent causes delayed shoot growth, seedling growth and chlorophyll content in sunflower (Helianthus annuus) and it could be safely used for irrigation purpose at low concentration.…”