Comparison the efficient reclamation of different inorganic materials with organic amendments to rice-wheat crop sustainable production in salt-affected soils

Abstract

Amelioration of salt-affected soils requires an integrated management approach, which not only improves their effectiveness for improving soil properties, but also increases the crop production and quality of the produce. Hence, a study was planned to evaluate combined use of organic and inorganic amendments for better rehabilitation of salt affected soil in ricewheat cropping sequence from 2013 to 2016. Treatments included T1 - control, T2 - gypsum @ 100 SGR, T3 - CaCl2 @ 50% SGR, T4 - CaCl2 @ 50% SGR + biogas slurry @ 10 tˑha-1, T5 - H2SO4 @ 25% GR, T6 - H2SO4 @ 25% SGR + biogas slurry @10 tˑha-1. A saline sodic field was selected, prepared and leveled. Composite soil samples were collected and analyzed for pHs = 9.15, ECe (dS m-1) = 4.86, SAR (mmol L-1)1/2 = 42.52 and GR (tˑha-1) = 8.64. Experiment was laid out in RCBD with three replications. The inorganic amendments (gypsum and CaCl2) were applied 30 days before rice transplanting in the respective treatment plots, followed by leaching while biogas slurry was applied 15 days before transplanting and H2SO4 was applied with first irrigation. Recommended dose of fertilizer 120-110-70 NPK kg ha-1 for wheat (Inqlab-91) and 110-90-60 NPK kg ha-1 for rice (Shaheen Basmati) was applied. Soil samples were collected before application of amendment and after harvesting of each crop. Straw and grain/paddy yield data were recorded at maturity. Pooled data showed that grain/paddy and straw yield of wheat and rice crop was higher in T2 (gypsum @ 100% SGR), but statistically (P≤ 0.05) non significant with T4 (CaCl2 @ 50% SGR + biogas slurry @ 10 tˑha-1). T3 (CaCl2 @ 50 % SGR) was at par with T6 (H2SO4 @ 25% SGR + biogas slurry @ 10 tˑha-1), followed by T5 (H2SO4 @ 25% SGR). The minimum yield was recorded in T1 (control). Soil analysis showed that pHs, ECe and SAR were significantly decreased in T2, (Gypsum @ 100% SGR), followed by T4 (CaCl2 @ 50% SGR + biogas slurry @ 10 tˑha-1). Hence, CaCl2 @ 50% SGR + biogas slurry @ 10 tˑha-1 may be an effective alternative reclamation strategy for areas that are restricted use because of salinity.