Leaching of nitrogen and base cations from calcareous soil amended with organic residues

Abstract

The potential for groundwater and surface water pollution by nutrients in organic residues, primarily nitrogen (N) and base cations (K+, Na+, Ca2+, Mg2+), is a consideration when applying such residues to land. In this study, we used a laboratory column leaching procedure to examine the leaching of N, K+, Na+, Ca2+ and Mg2+ in soils treated with two types of raw organic residues (poultry manure and potato residues) and one municipal waste compost, which are currently recycled on agricultural land in Iran. Each organic residue was thoroughly mixed with two different soils (sandy loam and clay) at the rate of 3%. Soil columns were leached at 4-d intervals for 92 d with distilled water, and effluents were analysed for pH, EC, nitrate (NO3(-)-N), ammonium (NH4(+)-N) K+, Na+, Ca2+ and Mg2+. The results indicated that the amounts of NO3(-)-N and NH4(+)-N leached from the poultry manure and potato residues could represent very important economic losses of N and pose an environmental threat under field conditions. The sandy loam soil amended with poultry manure lost the highest amount of NO3(-)-N (206.4 kg ha(-1)), and clay soil amended with poultry manure lost the highest amounts of NH4(+)-N (454.3 kg ha(-1)). The results showed that a treatment incorporating 3% of municipal waste compost could be used without negative effects to groundwater N concentration in clay soil. Significant amounts of K+, Na+, Ca2+, and Mg2+ were leached owing to the application of poultry manure, potato and municipal waste compost to soils. There was a positive relationship between K+, Na+, Ca2+, and Mg2+ with NO3(-)-N and NH4(+)-N leached in soils. Analysis of variance detected significant effects of amendment, soil type and time on the leaching NO3(-)-N, NH4(+)-N, K+, Na+, Ca2+ and Mg2+.

Assessing the Effect of Intensive Agriculture and Sandy Soil Properties on Groundwater Contamination by Nitrate and Potential Improvement Using Olive Pomace Biomass Slag (OPBS)

“…The higher N-NO 3 − concentrations reported in the study area were mainly due to the shallow depth of the water table and the aerated conditions allowing the continued oxygenation of the soil and groundwater. According to Zarabi and Jalali [44], N-NO 3 − is the predominant form in N leachate solution due to its high solubility and lower affinity to be adsorbed by soil sites. The following conversion equation was used to express nitrate concentration in the leached solution.…”

Leaching of Base Cations from Dairy Slurry Applied to an Agricultural Volcanic Ash Soil

“…The study of elements leaching through the soil is a key topic in the fields of soil fertility, plant nutrition, diffuse pollution, and soil hydrology (Hopmans and van Genuchten 2005). Approaches to study this issue can be divided into the following: (i) soil column studies under laboratory conditions (Escudey et al 2007;Zarabi and Jalali 2012) and (ii) in situ studies with ceramic cups (suction lysimeters) installed in the soil (Alfaro et al 2008;Salazar et al 2012). The first allow for an enhanced manipulation of environmental variables and liquid volumes applied to the columns, along with an easier collection and evaluation of liquids that have percolated through the soil.…”

“…The first allow for an enhanced manipulation of environmental variables and liquid volumes applied to the columns, along with an easier collection and evaluation of liquids that have percolated through the soil. However, they are not a perfect simulation of field conditions; there is, for example, an absence of plants inside the columns, and the soil structure is disturbed when the columns are filled (Zarabi and Jalali 2012). The in situ studies, on the other hand, allow for a more realistic evaluation of the environmental factors affecting the undisturbed soil (i.e., rain or irrigation); however, there are some technical complications when it comes to obtaining representative leachate samples (Wang et al 2012), and water samples cannot be continuously acquired, as in laboratory studies.…”

“…Studies on leaching in agricultural systems have mainly been conducted for key nutrients (nitrogen, phosphorus, potassium; e.g., Alfaro et al 2008;Salazar et al 2012). However, there are many other components of mineral and organic fertilizers, such as micronutrients (Zarabi and Jalali 2012) and trace metals, that are relevant to measure (Escudey et al 2007). Since there is a growing trend to use organic amendments in agriculture, such as residues from pig, poultry, and cattle farms, as well as compost produced from municipal waste (Zarabi and Jalali 2012), considering only key nutrients overlooks the possibility that soils may also be enriched in other chemicals.…”

“…However, there are many other components of mineral and organic fertilizers, such as micronutrients (Zarabi and Jalali 2012) and trace metals, that are relevant to measure (Escudey et al 2007). Since there is a growing trend to use organic amendments in agriculture, such as residues from pig, poultry, and cattle farms, as well as compost produced from municipal waste (Zarabi and Jalali 2012), considering only key nutrients overlooks the possibility that soils may also be enriched in other chemicals. In this regard, there is a relative lack of knowledge related to the base cation leaching that can occur when fertilizers, especially dairy slurry, are applied to volcanic ash soils.…”