Effects of Different Rice-Crab Production Modes on Organo-Mineral Complex Status in Soil Effects of nitrogen sources and potassium levels on growth and nutrient content of hybrid, its parent and conventional rice Arsenic tolerance, uptake and translocation by seedlings of three rice cultivars Effects of different rice-crab production modes on soil labile organic carbon and enzyme activities EFFECTS OF DIFFERENT RICE-CRAB PRODUCTION MODELS ON RICE-CRAB YIELD AND QUALITY