Effect of humic acid foliar spraying and nitrogen fertilizers management on wheat yield

<p>Foliar feeding has been used as a mean of supplying supplement doses of minor and major nutrients, plant<br>hormone, stimulants and other beneficial substances. It is reported that foliar application of humic acid enhances<br>the nitrogen use efficiency by crops because it is effective at ameliorating the leaf intevenal chlorosis that<br>occurred during early growth of wheat seedlings and hence improves yield. To test this hypothesis an experiment<br>was planned to see the effect of foliar application of humic acid on nitrogen use efficiency on grain and straw yield<br>of wheat in split plot design with three replications at Soil Chemistrty Section, Ayub Agricultural Research<br>Institute, Faisalabad during 2012-13. Experiment included two levels of foliar humic acid spray (H1: 0 and H2: 40<br>mg/L) in main plot and five levels of nitrogen fertilizer (N1: 0, N2: 60 kg/ha, N3: 90 kg/ha, N4: 120 kg/ha, N5: 150<br>kg/ha nitrogen from urea) in subplots. Foliar spray of humic acid was done at two stages i.e. at tillering and at<br>booting stage. At maturity, grain and straw yield was recorded. Interaction effect of foliar humic acid spraying<br>and nitrogen fertilizer management on grain yield and straw yield showed statistically significant results at 5%<br>probability level. The highest grain yield (5.02 t/ha) was obtained from use of 40 mg/L HA+ 150 kg N/ha<br>nitrogen fertilizer. Whereas N4H2 and N5H1 gave statistically similar yield i.e. 4.58 t/ha. Nitrogen use efficiency<br>was also improved in all treatments where 40 mg/L humic acid foliar spray was used along with nitrogen<br>fertilizer with maximum value of 68 in treatment receiving 60 kgN/ha+ 40ppm HA foliar spray.