Mitigating salinity stress and improving cotton productivity through integrative use of gypsum and compost amendments with exogenous proline

Abiotic constraints, such as salinity, significantly damage crop yields worldwide. Cotton, though moderately salttolerant, suffers from reduced growth and yield under saline-sodic soil conditions. Effective integrated mitigation strategies are crucial to address this challenge. Our study, conducted in Lodhran, Punjab, Pakistan, investigated six treatments using an integrated strategy such as gypsum, compost and exogenous proline combining effect in improving cotton productivity under salinity stress. We assessed plant growth, agronomic traits, physio-chemical parameters, cotton yield, and soil characteristics. Our experimental results showed that the combined application of amendments such as T5: gypsum + proline and T6: compost + proline gave better results as compared to individual treatments (T2, T3 & T4) over the control (T1). A significant improvement was observed in plant length and dry weights of shoot and root by 64 %, 81 % and 47 %, respectively under the effect of T5, also increased cotton yield up to 2 folds (888 kg) over control (324 kg ha-1 ). Likewise, significant improvement in the plant physio-chemical parameters was recorded such as high activities of antioxidant enzymes and the maximum accumulation of malondialdehyde (MDA) content by 60 -71 %, as well as reduction in the oxidative burst by 55 -65 % after the integrated treatments (T5 & T6) as compared to salt-stressed plants (control). Likewise, contents of nutrients are improved in plants viz., N: 70; P: 61 %; K: 33 % and Mg: 86 % under the positive effect of gypsum + proline over control. Results of soil analysis showed that the soil was moderately saline-sodic. Furthermore, soil analysis revealed that there was a significant improvement in NPK, S and Mg content in the soil after treated salt-stressed soil with gypsum and compost (T2, T3, T5 and T6) while a significant reduction was observed in Ca (17 %) and Na content (28 %), as well as EC (dSm- 1 ) was decreased by 38 % and SAR (mmol/ L)1/2 by 27 % under the effect of gypsum + proline over the control treatment. The outcomes of the current study reveal that the reclamation potential of gypsum and compost applied individually or together with exogenous proline improved plant growth, yield and plant defense system under salinity stress.