Nutrient dynamic study in potato crop under residue mulching and rate of phosphorus application
摘要
Phosphorus is a very essential nutrient for potato due to its high requirement and poor availability in acidic soil. Residue improves soil microbial and enzymatic activity thereby improves availability of nutrients. Therefore, the study was conducted on how additional P-fertilization and residue mulch together affect tuber yield, N, P, K availability, uptake and their efficiencies The experiment was conducted in split-plot design with three mulch levels as main plot (rice straw mulch (RSM), maize stover mulch (MSM) and un mulched (UM)) and four rates of phosphorus application as sub-plots (0, 40, 80, 120 kg ha−1). P application of 120 kg ha−1 with residue mulch reported significantly highest tuber yield under RSM (16.19 t ha−1) followed by MSM (15.74 t ha−1) and UM (13.29 t ha−1). Residue mulch has significantly increased soil microbial biomass carbon (SMBC), nitrogen (SMBN), and phosphorus (SMBP) by 10.1%, 8.4%, and 9.6%, respectively and also enhanced acid phosphatase activity by 8.9%, indicating improved microbial activity and nutrient cycling. Increasing the rate of P application increased tuber yield soil N, P and K availability. Mulch along with P application at 80–120 kg ha−1 increased tuber N uptake (87.13 to 100.41 kg ha−1), P uptake (16.54 to 19.56 kg ha−1), K uptake (84.86 to 98.89 kg ha−1) and also improved nutrient harvest index, mobilization efficiency ratio, and partial factor productivity of N, P, K. The study found that nitrogen and phosphorus mobilization efficiency indices showed a strong positive correlation with haulm yield, suggesting better nutrient mobilization directly improves yield and biomass production. Residue mulching combined with 80–120 kg P ha−1 is an effective strategy for acidic soils, improving soil health, nutrient uptake, and tuber yield, and can be recommended for sustainable potato production.