Physiological Response of Cowpea in a Rainfed Alfisol Ecosystem to the Impulse of Soil Mois- Ture Conservation Practices

Proven techniques of soil moisture conservation were imposed in two consecutive seasons (2002 and 2003) under a rainfed alfisol ecosystem in order to investigate the physiological response of cowpea as the test crop. The impulsive variations in soil moisture status with reference to these techniques were found to influence the physiological and biochemical parameters of cowpea significantly. Mulching was applied alongside the moisture conservation techniques for a complement analysis. Ridges and furrows with mulching (2002) and tied ridges with mulching (2003) led to higher chlorophyll content (1.88 and 1.54 mg g-1 FW) and chlorophyll stability index (87.28 and 83.97%) when compared to the traditional farmers’ practice. Leaf relative water content was higher (by 6.24%) in tied ridges with mulching. Accumulation of proline was observed during the second year mainly due to soil moisture stress induced by poor rainfall distribution. Mulch treatments resulted in a lower proline content (132.53 and 130.44 μg g-1 DW) while the farmers’ practice showed higher proline accumulation (214.33 μg g-1 DW). Ridges and furrows resulted in a higher grain yield (715.9 kg ha-1) when coupled with mulching (2002). Tied ridges with mulching (2003) also produced nearly the same effect (297.4 kg ha-1) over farmers’ practice.