Reduction of Ammonia Loss from Urea through Mixing with Humic Acids Isolated from Peat Soil (Saprists)

Regis Bernard,Mohamadu Boyie Jalloh,Osumanu Haruna Ahmed,Nik Muhamad Ab Majid

doi:10.3844/ajessp.2009.393.397

Abstract

Problem statement: Application of urea as a source of nitrogen fertilizer has an adverse effect on ammoniacal loss to the environment. This study was conducted to reduce ammonia loss from urea by mixing with Humic Acids (HA) isolated from Saprists peat. Approach: The effects of urea amended with four different amounts of humic acids, 0.25, 0.50, 0.75 and 1.00 g were evaluated in laboratory conditions using a closed dynamic air flow system. The mineral soil that was used as medium for the study was Bekenu series (typic paleudults). Amnonia loss, soil pH, exchangeable ammonium, available nitrate, exchangeable K, Ca, Mg and Na were determined using standard procedures. Results: All the treatments with HA significantly reduced ammoinia loss compared to urea alone. Increasing the amount of HA also significantly retained soil exchangeable ammonium and available nitrate. Treatments with HA had no significant effect on the concentrations of Mg, K and Ca, except for Na. The effect of HA in the mixtures on ammonia loss was related to their effect on the formation of ammonium over ammonia. Conclusion: Surface-applied urea fertilizer efficiency could be increased when coated with 1.00 g of HA.

Highlights

As Malaysia strives to become one of the leading agro based nations in South-East Asia, efficient use of fertilizers nitrogenous fertilizers such as urea cannot be overemphasized as most of the agricultural land is poor in nitrogen, a nutrient vital for plant growth and development
The exchangeable ammonium, available nitrate and Cation Exchange Capacity (CEC) of the soil were low while the organic matter was high for a sandy clay loam
Based on the results of this study, application of urea mixed with Humic Acids (HA) isolated from peat soil could provide better urea use efficiency

Summary

Introduction

As Malaysia strives to become one of the leading agro based nations in South-East Asia, efficient use of fertilizers nitrogenous fertilizers such as urea cannot be overemphasized as most of the agricultural land is poor in nitrogen, a nutrient vital for plant growth and development. Ammonia loss from fertilizers is a major problem confronting farmers. This problem arises especially using ammonia based Nitrogen (N) fertilizers such as anhydrous ammonia, ammonium nitrate and urea. Urea in particular has the potential of volatilizing into ammonia gas and escape into the atmosphere, reducing the N availability in the soils when it is surface broadcast on soils[1,2]. The factors which influence ammonia volatilization include levels of urease activity, availability of moisture, soil texture and nitrification rate. The main concern at present is the pH-buffer capacity and Cation Exchange Capacity (CEC) of the soil, as well as the presence of soil organic matter

Methods

Results

Discussion

Conclusion