System Productivity and Balance of Soil Phosphorus in Rice - Zero till Maize (Zea mays L.) Cropping System as Influenced by Levels of Phosphorus

Aims: To study the phosphorus requirement of Rice - zero till maize (Zea mays L.) cropping system on system productivity and soil available Phosphorus balance.

Study Design: Randomized block design (two factors).

Methodology: The field experiment was conducted for two consecutive years at the College of Agriculture, Rajendranagar, Hyderabad. Levels of P2O5 (kg ha-1) applied to rice (5 levels) and maize (3 levels) 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: In terms of system productivity (maize grain equivalent yield kg ha-1 annum-1) of rice–maize cropping system, the P40-60 and P30-60 treatments were found better than other Phosphorus management strategies.

The balance sheet of available Phosphorus in soil at the end of fourth season revealed that input-output balance was positive with P40-60 and P30-60 by specifying the application of 30 kg P2O5 ha-1 and/or 40 kg P2O5 ha-1 to rice and 60 kg P2O5 ha-1 to maize in rice-zero till maize cropping system.