Sharif, Muhammad (2002) EFFECT OF LIGNITIC COAL DERIVED HUMIC ACID ON GROWTH YIELD OF WHEAT AND MAIZE IN ALKALINE SOIL. PhD thesis, University Of Agriculture, Peshawar.
Lignitic coal derived Humic Acid (HA) has shown promising results as low cost natural fertilizer source with persistent effect on soil conditions and crops yield. Different experiments were conducted to study the effect of HA on the growth and yield of maize and wheat in pots as well as in field. Pot experiment was conducted to study the effect of different levels of HA on the growth of maize (Zea mays. L. Kissan) using Tarnab soil series (fine silty mixed hyperthermic udic haplustepts). Humic acid was sprayed at the rate of 0, 50, 100, 150, 200, 250 and 300 mg kg-1 soil. The addition of 50 and 100 mg kg-1 HA caused significant (P < 0.05) increases of 41 % in shoot and 39 and 32 % in root dry weight of maize plants as compared to control. Addition of HA increased soil N concentration and plant N accumulation significantly (P < 0.05) over control with no significant differences within the treatments of different levels of HA applied. Soil P concentration improved significantly (P < 0.05) by the addition of 200 mg kg-1 HA whereas plant P accumulation was not significantly affected by the application of different levels of HA. Zn, Fe, Mn and Cu concentrations of soil and their accumulations by maize plants increased non-significantly by the addition of HA. Field experiment was conducted in the research farm of NWFP Agricultural University Peshawar to study the effect of 0, 0.5 and 1.0 kg ha-1 of HA alone (F 0) and in combination with two levels of NPK, 60-45-30 kg ha-1 (F I) and 120-90-60 kg ha-1 (F II), respectively on the extent to which the yield and nutrients accumulations of wheat (Triticum aestivum L. Fakhr-e-Sarhad) are affected Addition of 0.5 and 1.0 kg ha-1 HA at F 0, F I and F II levels of NPK increased grain and dry matter yield of wheat significantly (P < 0.05) over control. Addition of 0.5 kg ha-1 HA produced 25 % significantly higher grain yield (4.8 Mg ha-1) than control, which was statistically similar with 1.0 kg ha-1 HA, at F 0 and FI level of NPK. Addition of 0.5 kg ha-1 HA at F I produced 26 % significantly (P < 0.05) higher yield of 6.0 Mg ha-1 than the 0.5 kg ha-1 HA at F0, which was statistically similar to1.0 kg ha-1 HA and to all level of NPK. Straw yield of wheat improved non-significantly with the addition of HA at given levels of NPK. Soil N and P concentrations increased significantly (P < 0.05) with NPK but non-significantly with HA treatments over control. Addition of 0.5 and 1.0 kg ha-1 HA at F 0 and F I levels of NPK improved N and P accumulations by wheat plants significantly (P < 0.05). Post harvest soil concentrations of Zn, Mn Fe and Cu improved non-significantly with the addition of HA. The total plants accumulation of Fe and Cu increased significantly (P < 0.05) whereas Zn and Mn accumulation improved non-significantly with the addition of HA at F I and F II level of NPK. Experiment on the residual effect of HA was conducted in the same lay out used for wheat to determine the extent to which the yield and nutrients accumulations by maize plants (Zea mays. L. Kissan) grown after wheat are affected. The residual effect of the addition of 0.5 and 1.0 kg ha-1 HA caused significant (P < 0.05) increases in grain, total dry matter and in stalk yield of maize. Post harvest soil N concentration increased significantly (P < 0.05) with the residual effect of the addition of HA. Soil P concentration was non-significantly affected with the residual effect of HA. Residual effect of the addition of NPK levels showed significant (P < 0.05) response for total N accumulation by maize plants whereas HA levels increased N accumulation non-significantly over control. Plant P accumulation was significantly (P < 0.05) increased over control with residual effect of the addition of 0.5 and 1.0 kg ha-1 HA at F 0 and F I levels of NPK. As compared to control, the residual effect of the addition of 0.5 and 1.0 kg ha-1 HA at F 0 showed significant (P < 0.05) increase in soil Zn concentration. Soil Fe and Cu concentrations increased significantly (P < 0.05) with the residual effect of 1.0 kg ha-1 HA at F I and F II levels of NPK. Soil Mn concentration was affected non-significantly. Plants accumulations of Zn, Mn, Fe and Cu were improved non-significantly with the residual effect of the addition of HA at F 0, F I and Fll levels of NPK. Laboratory experiments were conducted to investigate the effect of HA on physicochemical and biological properties of soil. Soil samples were incubated aerobically at 30°C for 28 days. The CO2 evolution was measured at 1, 4, 7, 10, 13, 16, 19, 22, 25 and 28 days of incubation. Microbial population, cation exchange and water holding capacities of the soil samples were measured at the end of 28 d of incubation period. Rate of CO2 evolution reached to maximum at 4 d for control treatments but with HA and NPK treatments it reached to maximum values at 7 d and then decreased progressively to minimum values on 28 d of incubation. Addition of 0.3 and 0.6 mg kg-1 HA produced identical increases of 142 % at F 0, 120 and 125 % at F I and 96 and 104 % at F II level of NPK over control in the rate of CO2 evolution. The rate of CO2 increased by 67 and 100 % over the control at FI and F II alone. Humic acid and NPK treatments showed additive effect on CO2 production particularly at low levels through out the incubation period. Addition of 0.3 and 0.6 mg HA kg-1 soil increased bacterial population by a factor of 4 to 6 at FO and 16 to 19 at F I and FII, where as the fungal population increased by 7 to 8 times at F 0 and 9 to 16 times at F I and F II. Cation exchange capacity of the soil increased by 14 to 29 % and 10 to 21 % with levels of HA with and without NPK, respectively. Soil available water holding capacity was changed slightly with addition of HA applied alone and or with NPK. Results suggested that addition of HA at F I level of NPK produced significant and economical wheat yield with maximum nutrient accumulation. Significant maize yield with improved nutrient accumulations was recorded as residual effect of the addition of HA at F II level of NPK. The beneficial effect of HA appears to be associated with its chelating power of nutrients along with its impact on physicochemical and biological properties of soil. The magnitude of increases observed in population and activity of microorganisms, CEC and WHC might explain for the increases observed in crop yield caused by the addition of HA at low levels. Humic acid offers great promise as low cost and environment friendly fertilizer for crop production.
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Lignitic coal, Maize, Alkaline soil, Humic acid, Soil analysis, Plants analysis, Chemical fertilizer, Grain, Total Dry Matter, Straw Yield, Soil organic matter content, Properties of soil, Zea mays L. Kissan, Tarnab soil series, Triticum aestivum L. Fakhr-e-Sarhad,|
|Subjects:||Agriculture & Veterinary Sciences(a)|
|Deposited By:||Mr Ghulam Murtaza|
|Deposited On:||16 Jun 2006|
|Last Modified:||11 Mar 2015 22:20|
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