Growth, yield and quality of wheat (Triticum aestivum) as influenced by organic sources of nitrogen nutrition

A field experiments were conducted for five years from 2003-04 to 2007-08, during rabi seasons at G.B. Pant University of Agriculture & Technology, Pantnagar, on Mollisols under the Tarai region of the Uttarakhand, to study the effect of organic sources of nitrogen nutrition on growth, productivity and quality of wheat {Triticum aestivum (L.) emend. Fiori & Paol}, PBW 343. Fourteen treatments with three replications were laid out in a randomized block design (fixed plot). Four nitrogen doses i.e. 125, 100, 75 and 50% of the recommended dose of nitrogen (RDN=150 kg/ha) were applied through each of the three organic sources i.e. FYM, vermicompost and neemax. Urea as inorganic source for recommended nitrogen and control (no nitrogen) was also tested for comparison of the results. The study showed that RDN through urea gave maximum wheat yield (4.63 t/ha), which was signifi- cantly higher than other treatments. Among the organic sources of nitrogen nutrition, FYM @ 125% of RDN gave maximum wheat yield (3.65 t/ha), which was at par with vermicompost and neemax at same rate but significantly higher than FYM @ 50% of RDN. Morphological determinants viz. emergence count/m2, plant height (cm), dry matter accumulation (g/m2) and yield contributing characters, i.e., spike/m2, grains/spike1 and 1,000-grains weight (g) were also significantly higher under N nutrition through urea than others, but FYM, vermicompost and neemax @ 125% of RDN gave significantly higher value of these parameters than their respective nitrogen nutrition @ 50% . Protein content, protein yield, nitrogen uptake and nitrogen use efficiency indicators, which higher under ni- trogen nutrition through urea, than those under organic sources of nitrogen. Among the organic sources, vermicompost resulted in maximum value of protein content, protein yield and nitrogen harvest index than others. However, nitrogen use efficiency indicators i.e., physiological, agronomic and recovery efficiency were higher un- der FYM treated plots. All of the organic treatments except 50% of RDN through neemax and 50% of RDN through vermicompost were highly promising. All the treatments except control maintained a positive balance of nitrogen in soil. High cost involved in procuring large quantity of FYM and vermicompost resulted in negative net returns un- der these treatments.