Response of Potato Yield, Soil Organic Matter, Microbial Properties, and Pesticide Residues to Different Cropping Systems and Nutrient Management in North Pakistan

Pesticide residue contamination in potato field is posing a significant threat to health and the environment. Hence, pesticide residue management is a need of time. Thus, the present study was conducted with objectives of minimizing pesticide residue using cropping system (CS) and nutrient management (NM) treatments. Treatments include two CS, i.e. CS₁ (potato-mungbean), CS₂ (potato-maize) and six NM (NM0 (no use of fertilizers), NM1 (poultry manure @ 20 t ha⁻¹), NM2 (compost @ 20 t ha⁻¹), NM3 (farmyard manure (FYM) @ 20 t ha⁻¹), NM4 (NPK recommended dose), and NM5 (biofertilizer PSB 2.5 kg ha⁻¹ + NFB 2.5 kg ha⁻¹) + FYM @ (10 t ha⁻¹) + half recommended dose of N-P-K (Urea-DAP-SOP)). A study was conducted at a pesticide-contaminated field of village Tajak tehsil Hazro, district Attock. Data about tuber yield, biological yield, harvest index, soil microbial biomass carbon (MBC), soil microbial biomass nitrogen (MBN), and pesticide residue (bifenthrin and imidacloprid) in soil and plant were collected from all treatments during 3 years (2018 to 2020). Results showed that potato-mungbean cropping system significantly increased biological (2.5%) and tuber yield (2.9%) as compared to CS₂. Application of FYM in combination with biofertilizer and 50% recommended dose of NPK resulted in higher biological yield (43.2%) and tuber yield (74%) as compared to control. Potato-mungbean CS reduced bifenthrin (5.9%) and imidacloprid (4.0%) residues significantly as compared to the CS₂, while NM5 significantly decreased the residues bifenthrin (46.61%) and imidacloprid (62.96%) as compared to the control. A positive relationship was observed between MBC and MBN with biological and tuber yield, while the association was negative with pesticide residues. Hence, it can be concluded that a legume-based cropping system with NM5 could help minimize pesticide contamination by increasing MBC and MBN, which could further lead to sustainable potato yield under contaminated fields.