Management of Phosphorus on Performance of Rice - Zero till Maize (Zea mays L.) Cropping System

Aims: To study the phosphorus levels in Rice - zero till maize (Zea mays L.) cropping system on yield, nutrient uptake and post-harvest soil nutrient status.

Study Design: Two factors Randomized block design.

Methodology: Field investigation was organized during two consecutive years at College of Agriculture, Rajendranagar, Hyderabad. Levels of P2O5 (kg ha-1) applied to rice (5) and maize (3) respectively were (P0-30, P0-45, P0-60, P10-30, P10-45, P10-60, P20-30, P20-45, P20-60, P30-30, P30-45, P30-60, P40-30, P40-45 and P40-60).

Results: Direct effect of 20 kg P2O5 ha-1 to rice, being on par with 30 and 40 kg P2O5 ha-1, produced significantly higher grain and straw yield of rice, uptake of nutrients over rest of the treatments. The residual effect of Phosphorus applied to maize 60 kg P2O5 ha-1 resulted in significantly higher above said parameters of rice. The cumulative effect of P20-60 produced significantly higher grain and straw yield, nutrient uptake of rice over P10-30, P10-45, P0-30, P0-45 and P0-60 treatments.

Direct effect of 60 kg P2O5 ha-1 to maize recorded significantly higher grain and stover yield, nutrient uptake and available soil phosphorus over lower Phosphorus levels; but the soil nitrogen and potassium followed reverse trend. The residual effect of 40 and /or 30 kg P2O5 ha-1 applied to rice had a greater positive influence on the above said parameters except soil nitrogen and potassium over lower phosphorus levels. The cumulative effect of P40-60 and P30-60 had produced significantly higher grain and stover yield and nutrient uptake of maize and showed significantly higher available soil phosphorus at the end as compared to the rest of the treatments; emphasizing application of 30 kg P2O5 ha-1 to rice and 60 kg P2O5 ha-1 to maize through P30-60 treatment in rice-zero till maize cropping system to maintain phosphorus sustainability.