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The influence of three rates of each of N, P and K fertilizers on the availability of native and applied Mn to wheat was studied in a field experiment on an alluvial soil of the Indo-Gangetic plain. Increasing dressings of N as ammonium sulphate resulted in consistently higher yields and Mn uptake by the crop. Concentration of Mn in the grain increased with increasing N dressings when native Mn and Mn fertilizer supplied this nutrient but it was unaffected in plants sprayed with Mn. Adding P as superphosphate tended to lower the concentration of Mn in the grain when relying on native or applied Mn but it significantly enhanced the crop yield and total Mn uptake. Applying K as muriate of potash slightly depressed Mn uptake by plants. Potassium had a more pronounced effect in the absence of P fertilizer. The concentration of Mn in the straw was not significantly affected by N, P and K fertilization.

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A wide-mouthed pycnometer was employed for rapid determination of soil water. The principle involved is to weigh the pycnometer when filled with the soil sample and water. The particle density of soil needs to be known. There is no necessity to add exact volumes of water. For the 7 soils studied, the water content values obtained by the proposed method were similar to those by oven-drying.

Rice yield increased significantly and consistently up to 120 kg N/ha when weeds were not controlled. But when weeds were effectively controlled by two hand weedings (20 and 40 days after transplanting) or by use of thiobencarb at 1-0 kg a.i./ha rice yield increased significantly up to 80 kg N/ha. The optimum dose of N for transplanted rice under mid-hill conditions of Himachal Pradesh (Palampur) was 82 kg/ha when two hand weedings were done and 86 kg/ha when weeds were managed using thiobencarb. The yield response per kg of N in the respective treatments was 20 and 24 kg of grain. The weed dry weight was significantly lower in thiobencarb and hand weeded plots compared with unweeded check though the difference in weed dry weight due to the former two treatments was not significant.