Effects of inorganic phosphorus fractions under different tillage practices on wheat (Triticum aestivum) in an acid soil of West Bengal (India)

Phosphorus (P) is an essential element for plant growth and is usually applied to soil as inorganic P fertilizer. An experiment was conducted to study the effect of inorganic phosphorus fractions and tillage operations (conventional and zero tillage) on the yield of the crop. The field experiment was laid out in a randomized block design with nine treatments replicated three times. Recommended dose (RD) of fertilizer (kg/ha) of N:P:K @100:60:40 (RD) was modified in different treatments as ; T₁ (untreated control), T₂ (NP as RD), T₃ (K+P as RD),T₄ (NK as RD +P as 25% of RD)], T₅ [NK as RD and P as 50% of RD ],T₆ [NK as RD and P as 75% of RD; T₇ [NKP as RD], T₈ [NK as RD and P as125% of RD ] and T₉ [NK as RD and P as 150% of RD] . Surface soils were collected (0-20 cm depth) from each plot and important soil properties were studied. The soil was acidic in reac-tion having pH- 5.6 and EC of 0.06 dSm^-1. The available N-P-K in soil was 126.34 kg/ha, 20.13 kg/ha and 133.28 kg/ha respectively. The inorganic forms of phosphorus (Ca-P, Al-P, Fe-P, Re-P), in soils during the experimental period showed higher fractions in the conventional tillage than the zero tillage operation. The Al-P fraction of soil affected significantly (P=0.05) towards the yield of the crop (wheat) compared to other P-fractions.