Investigating Combination and Individual Impact of Phosphorus and Humic Acid on Yield of Wheat and Some Soil Properties

Abstract

In order to evaluate the effect of different levels of Phosphorous (P) alone and in combination with Humic acid (HA) on the yield and P accumulation by wheat(TriticumaestivumL, CV Fakhr-e-Sarhad)., a field experiment was carried out at agriculture research station of Swabi, Pakistan during 2016-2017. A total of eight treatments replicated four times were arranged in Randomized Complete Block Design (RCBD) in the field. Two levels of HA including control (H0: control and H1: 500 g ha-1) and four levels of P (P2O5) including control as Single Super Phosphate (SSP) (P0: control, P1: 60 kg ha-1, P2: 90 kg ha-1, and P3: 150 kg ha-1) were utilized. ; Size of each plot was kept to 5x4 m. Addition of different levels of SSP alone and in combination with HA significantly (P<0.05) improved straw, grain and total wheat yield over control. HA in combination with 60 and 90 kg P2O5 ha-1 improved the grain yield by 22.4 and 6.5 % respectively as compared to the same amount of fertilizer applied alone. Total yield (Dry mass + Grains) of 20877 kg ha-1 was produced by the treatment P2H1 (90 kg P2O5 ha-1 + 500 g ha-1 HA) followed by the treatment P2H0, which were 78.69 and 75.03 % increases over the control. Significantly highest 1000- grain weight of 47.8 g was recorded in the treatment P2H1 while all other treatments showed non-significant increase in 1000- grain weight. Unlike soil pH values, improvement in the Soil Organic Matter content (SOM) was observed with the application of both HA and chemical fertilizers either applied alone or in combination. SSP applied either alone or in combination with HA increased significantly (P<0.05) the post-harvest soil P concentration as well as P accumulation by wheat plants over control. Results suggest that application 90 kg P2O5 ha-1 reinforced with HA (P2H1) may be considered as an optimum dosage for achieving optimum yield of wheat crop.