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The present study was conducted to characterize the nature of salinity, to understand the relationship between pH, EC, Ca, SAR and ESP and to develop leaching curves for the Kalipatnam drainage pilot area, India. Soils are saline sodic. A relation was developed between the ECe and EC 5 for routine soil analysis. A negative correlation was observed between pH and salinity. A regression equation was developed between SAR and ECe of the soils. Variations in soluble Ca 2þ ion concentrations between soils were negatively related to soil pH and positively related to soil salinity. A negative relation was observed between organic carbon and ESP. Gapon's coefficient for these soils is 0.031 with a negative intercept of À0.499.Water requirements for leaching of saline soils of the Kalipatnam drainage pilot area were estimated. An irrigation depth of 30 cm leached about 50% of salts only in clay and sandy loam soils. The plateau after 50% salt reduction can be attributed to a shallow water table (40 cm only). Empirical equations are not useful for these soil conditions for predicting desalinization pattern. Leaching curves developed based on Yand DW/DS, where Y ¼ ECf À ECeq/ECi À ECeq will give better estimates than other relations.La présente étude a été conduite pour caractériser la nature de la salinité, pour comprendre les relations entre pH, EC, Ca, SAR et ESP et pour développer les courbes de lessivage concernant le secteur pilote de drainage, Kalipatnam, Inde. Les sols sont salin-sodiques. Une relation a été développée entre ECe et EC5 à partir des analyses de sol courantes. On a observé une corrélation négative entre le pH et la salinité. Une courbe de régression a été développée entre SAR et ECe. Les concentrations en ion Ca2þ soluble sont reliées négativement au pH et positivement à la salinité de sol. On a observé une relation négative entre le carbone organique et ESP. Le coefficient de Gapon pour ces sols est 0.031 avec une interception négative de À0.499.Les besoins en eau pour le lessivage des sols salins du secteur pilote de drainage de Kalipatnam ont été estimés. Une quantité de l'eau de 30 cm a lessivé environ 50% de sels seulement dans les sols argilo-sableux organiques. Le plateau suivant la réduction de sel de 50% peut être attribué à la faible profondeur de la nappe (40 cm seulement). Pour ces types de sol les équations empiriques ne sont pas utiles pour prévoir les conditions de desalinisation. Les courbes de lessivage développées sont basées sur Y et DW/DS, où Y ¼ ECf À ECeq/ECi À ECeq donne de meilleures estimations que d'autres relations.

An investigation was carried out to find out the relative incidence of pest complex in three cottoncultivars viz., in MECH 162 Bt, MECH 162 non-Bt. The treatments were replicated nine times in randomized block design. The incidence of leafhopper, aphid and whitefly was found in all the three cultivars throughout the crop season, but the worm, Helicoverpa armigera and spotted bollworm, Earias vittella infestation was comparatively less in MECH 162 Btcotton than other cultivars. The maximum incidence of H. armigera was recorded during 14 th and 15 th week after sowing in all three cultivars.

A field experiment was conducted at Regional Agricultural Research Station, Maruteru, Andhra Pradesh during kharif season of 2016 to study the site-specific nutrient management approaches for enhancing productivity and profitability in rice (Oryza sativa L.). Nutriexpert is a decision support tool developed by the International Plant Nutrition Institute (IPNI). Application of fertilizers based on the Nutriexpert was (112-31-58) higher nitrogen, lower phosphorus and potassium than the recommended dose of fertilizers (90-60-60) during kharif season for rice. The treatments included recommended fertilizer (T1), Site Specific Nutrient Management (SSNM) based on Nutrient expert (T2), SSNM based on Leaf Colour Chart (50% N as basal and rest 50% based on LCC (T3), T2 minus Nitrogen (T4), T2 minus Phosphorus (T5), T2 minus Potassium (T6), Absolute control (without N, P and K) (T7) and Farmer's Practice (T8) . The results revealed that the highest grain yield (6317 kg ha-1) and straw yield (7663 kg ha-1) of rice was recorded in T2- SSNM (NE) which is significantly superior over all other fertilizer treatments. Application of major nutrients based on nutriexpert recorded higher uptake of nitrogen (128.50 kg ha-1), phosphorus (27.15 kg ha-1), and potassium(137.32 kg ha-1). Nutrient omission and control treatments recorded significantly lowest grain and straw yields of rice and also nutrient uptake. Hence, nutriexpert not only saves the fertilizers but also helps in increased grain and straw yield of rice.