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ABSTRACT:This study was planned with hypothesis to quantify mineralization rate of wheat and groundnut straw spiked in Kahuta and Guliana soil series. Results revealed that groundnut and wheat strawspiked soils had increased quantum of microbial biomass carbon (Cmic), biomass nitrogen (Nmic) and biomass phosphorous (Pmic) and activities of enzyme dehydrogenase (DHA) and alkaline phosphatase (APA) than un-amended soils. Initially, the contents of soil Cmic, Nmic, Pmic, DHA, and APA increased gradually during 2-14 th days of incubation (DAI), again increased significantly at 28 th DAI and then decreased slowly at 60 th DAI in all treatments under both series. Hence, the addition of groundnut straw mineralized better than to other organic sources in both soil series. These results suggested that groundnut straw must be incorporated in soil one month before sowing of crop to enhance crop yield under rain-fed dry farming.

M aize (Zea mays L.) is an important cereal crop and cultivated under divergent climatic conditions of spring and summer seasons in Pakistan (Tariq et al., 2002). Being monoecious crop and very much sensitive to high temperatures (Ullah et al., 2020) which causes severe irreversible changes in Abstract | Temperature is a very important factor that affects crop yield. Maize, a monoecious plant, is adversely affected by high temperature during anthesis. Asynchronous fertilization and pollen desiccation reduce maize yield by reducing grain number and their size. Spray of hydrogen peroxide (H 2 O 2 ), salicylic acid (SA) and ascorbic acid (AsA) may induce heat stress tolerance. Spray of SA, AsA, and H 2 O 2 increased chlorophyll, relative water and nutrient contents, membrane stability index (MSI) and antioxidants activities in heat stress. Moreover, foliar application of chemicals during normal and late planting improved the grain yield by increasing both the grain number and size. Foliar spray of SA, AsA and H 2 O 2 may induce heat tolerance by improving antioxidant activities which stabilized membrane and maintaining relative water, chlorophyll and nutrient content in ear leaves of maize during heat stress.

In arid environment, limitations of crop productivity could be improved by soil management practices like soil conservation measures, tillage and reducing slopes through terracing on different cropping patterns. These patterns include area as Wheat-Maize (WMCP) and Wheat-Fodder (WFCP) in Kahuta (high rainfall climatic area), Wheat-Millet-Fallow (WMFCP) and Wheat- Millet-Lentil (WMLCP) in Khairimurat (medium rainfall climatic area) and Wheat-Fallow (WFCP) and Fallow-Groundnut (FGCP) in Pindi Gheb (low rainfall climatic area). In areas that have more crop water requirements the yield of these crops has been affected when the drought prevails. Our results evidenced that more average soil water content (ASWC) was available in high to medium height terraces in WMCP and low to medium in WFCP of Kahuta area. ASWC remained more in high to medium height terraces under all cropping pattern of Khairimurat during September. ASWC remained more in low to medium height terraces under all cropping pattern of Pindi Gheb during September and December. Equidistantly, soil water release curve also indicated that medium rainfall sites had more plant water availability as compared to high and low rainfall sites. Yield relationship to plant water availability revealed significance for intrusion of modified cropping patterns rather than existing cropping patterns on sustained basis. Finally, our study suggests that cropping patterns of high and low rainfall areas should adjusted by growing low water requirement crops in summer seasons to cope the drought period for the sustainability of agriculture under rainfed climatic conditions. Keywords : cropping patterns, Pothowar Plateau, soil water contents, soil water release curve, sloppy lands

In arid environment, limitations of crop productivity could be improved by soil management practices like soil conservation measures, tillage and reducing slopes through terracing on different cropping patterns. These patterns include area as Wheat-Maize (WMCP) and Wheat-Fodder (WFCP) in Kahuta (high rainfall climatic area), Wheat-Millet-Fallow (WMFCP) and Wheat- Millet-Lentil (WMLCP) in Khairimurat (medium rainfall climatic area) and Wheat-Fallow (WFCP) and Fallow-Groundnut (FGCP) in Pindi Gheb (low rainfall climatic area). In areas that have more crop water requirements the yield of these crops has been affected when the drought prevails. Our results evidenced that more average soil water content (ASWC) was available in high to medium height terraces in WMCP and low to medium in WFCP of Kahuta area. ASWC remained more in high to medium height terraces under all cropping pattern of Khairimurat during September. ASWC remained more in low to medium height terraces under all cropping pattern of Pindi Gheb during September and December. Equidistantly, soil water release curve also indicated that medium rainfall sites had more plant water availability as compared to high and low rainfall sites. Yield relationship to plant water availability revealed significance for intrusion of modified cropping patterns rather than existing cropping patterns on sustained basis. Finally, our study suggests that cropping patterns of high and low rainfall areas should adjusted by growing low water requirement crops in summer seasons to cope the drought period for the sustainability of agriculture under rainfed climatic conditions. Keywords : cropping patterns, Pothowar Plateau, soil water contents, soil water release curve, sloppy lands