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SUMMARYTopsoil depth and yields of sorghum, pearl millet and castor bean were found to be positively correlated when monitored over thirteen seasons under widely varying rainfall conditions on an Alfisol in Andhra Pradesh, India. Yields responded up to 2.5 times more to topsoil depth when rainfall in the critical period exceeded evapotranspiration than under drier conditions. Yield variations were explained by topsoil depth in cereals, and by the interaction between rainfall during the critical period and topsoil depth in cereals and castor bean (R2<0.72). The expected yield losses as a result of erosion, based on 56 years of rainfall data, were 138, 84 and 51 kg ha−1 cm−1 for sorghum, pearl millet and castor bean, respectively. Quadratic models explained the yield losses due to cumulative erosion under conditions of both poor and good rainfall during the critical period. Sorghum and pearl millet tended to produce no yield when erosion exceeded 34 cm and castor bean when it exceeded 40 cm. There was less reduction in yield when rainfall was poor, up to about 10 cm of erosion, than when rainfall was good. The results indicate that pearl millet and castor bean are more suitable than sorghum for low rainfall and eroded conditions.

S U M M A R YTopsoil depth and yields of sorghum, pearl millet and castor bean were found to be positively correlated when monitored over thirteen seasons under widely varying rainfall conditions on an Alfisol in Andhra Pradesh, India. Yields responded up to 2.5 times more to topsoil depth when rainfall in the critical period exceeded evapotranspiration than under drier conditions. Yield variations were explained by topsoil depth in cereals, and by the interaction between rainfall during the critical period and topsoil depth in cereals and castor bean (R 2 >O.72).The expected yield losses as a result of erosion, based on 56 years of rainfall data, were 138, 84 and 51 kg ha" 1 cm" 1 for sorghum, pearl millet and castor bean, respectively. Quadratic models explained the yield losses due to cumulative erosion under conditions of both poor and good rainfall during the critical period. Sorghum and pearl millet tended to produce no yield when erosion exceeded 34 cm and castor bean when it exceeded 40 cm. There was less reduction in yield when rainfall was poor, up to about 10 cm of erosion, than when rainfall was good. The results indicate that pearl millet and castor bean are more suitable than sorghum for low rainfall and eroded conditions. K. P. R. Vittal, K. Vijayalakshmi y U. M. B. Rao: Efecto de las Uuvias y erosion acumulativa sobre el rendimiento del sorgo, mijo perla y semilla de ricino bajo condidones de secano en Andhra Pradesh, India.R E S U M E N Al controlar la profundidad de la capa superficial del suelo y el rendimiento del sorgo, mijo perla y semilla de ricino a lo largo de trece temporadas bajo condiciones de lluva sumamente variadas en un Alfisol en Andhra Pradesh, la India, estos dos factores presentaron una correlation positiva. Los rendimientos respondieron hasta 2,5 veces mas a la profundidad de la capa superficial del suelo cuando la lluvia en el pen'odo cn'tico superaba la evapotranspiracion en comparacion con lo ocurrido bajo condiciones secas. Las variaciones en el rendimiento se explican por profundidad de la capa superficial del suelo en los cereales y por la interaction entre la precipitation durante el pen'odo cn'tico y la profundidad de la capa superficial del suelo en los cereales y en la semilla de ricino (R 3 >0,72). Las perdidasde rendimiento que se esperaban como resultado de la erosion, basadas en 56 anos de datos historicos sobre las precipitaciones, fueron de 138, 84 y 51 kg ha" 1 cm" 1 para el sorgo, mijo perla y semilla de ricino respectivamente. Los modelos cuadraticos explican las perdidas de rendimiento debido a la erosion acumulativa bajo condiciones tanto de buena lluvia como de precipitaciones escasas durante el pen'odo cn'tico. El sorgo y el mijo perla mostraron una tendencia de no producir ningun rendimiento cuando la erosion superaba los 34 cm y la semilla de ricino cuando excedia de los 40 cm. Hubo menos reduction en el rendimiento con poca lluvia hasta los 10 cm de erosion que cuando las lluvias eran abundantes. Los resultados indican que el mijo perla y la semilla d...

A field study was carried for two consecutive kharif and rabi seasons of 2013-14 and 2014-15 on farmer’s fields across 15 locations each year during kharif and 9 locations each year - during rabi in Srikakulam district, Andhra Pradesh. We tested five crop establishment methods viz., dry direct sowing using fertilizer-cum seed drill under irrigated conditions, drum seeding, systems of rice intensification (SRI), mechanized transplanting using rice 8 row yanmar transplanter, and manual transplanting. Study findings revealed that transplanting with rice planter emerged as high yielding method of establishment where the grain yield was higher by 9.21% over manual transplanting. Dry direct sowing was found to be highly profitable method of rice establishment by recording higher net returns Rs. 12596/ha compared to manual planting. Dry direct sowing and SRI proved as water productive rice establishment methods which took lesser water by 22.45% and 18.78% compared to manual transplanting during kharif. Whereas during rabi, drum seeding proved as profitable and water saving method of crop establishment in rice.