Land‐use Effects on Anion‐associated Cation Leaching in Response to Above‐normal Precipitation

Abstract

Fertilizers and liming agents are generally used to achieve optimal economic yields. However, several negative effects of long‐term annual fertilization of nitrogen (N) in particular have been observed, such as reduced cation exchange capacity and decreased base saturation, which may stimulate accelerated leaching loss of other nutrients. Equilibrium‐tension lysimeters installed at a depth of 1.4 m were used to evaluate leaching of soil‐solution ionic constituents from a tallgrass prairie restoration and optimally and deficiently N‐fertilized, no‐tillage (NT) and chisel‐plowed (CP) maize (Zea mays L.) agroecosystems on Plano silt loam soil (fine‐silty, mixed, superactive, mesic Typic Argiudoll). This study was conducted in south‐central Wisconsin, USA during a 1‐year period of above‐normal precipitation between January 2000 and January 2001. The loss of soluble constituents added to agroecosystems to maintain adequate soil fertility and pH, such as N, phosphorus, potassium, calcium, and magnesium, was generally numerically smaller from the natural prairie 25 years after conversion from cultivated agriculture than from optimally and deficiently N‐fertilized, NT and CP maize agroecosystems, though the differences were not significant. Tillage and fertilizer N‐rate generally did not significantly affect drainage, ionic concentrations, or their leaching losses in the maize agroecosystems, though all parameters evaluated tended to be numerically smaller in the deficiently than optimally N‐fertilized maize agroecosystems. Nitrate‐N leaching losses were generally significantly positively correlated with leaching losses of K, Ca, Mg, and Na in the maize agroecosystems, but not for the prairie, indicating that nitrate‐N leaching plays a significant role in the concomitant loss of cations to maintain soil‐solution charge balance in N‐fertilized maize agroecosystems in a temperate environment.

Soluble Metal Leaching from a Poultry Litter–Amended Udult under Pasture Vegetation

“…McLaren et al (2003) also reported no significant increase in leachate DOC collected at 70 cm after a single application of metal-spiked sewage sludge. The leachate DOC concentrations measured in this study are similar to that reported in leachate under a restored tallgrass prairie (3.1 mg DOC L 21 ; Brye and Norman, 2004). These observations are also supported by Keller et al (2002) who demonstrated that DOC leaching is not an immediate significant loss mechanism for C applied in organic soil amendments.…”

The potassium paradox: Implications for soil fertility, crop production and human health

“…A further difficulty arises from the mobility of Cl − in soils, which intensifies profile leaching of Ca 2 + as a counterion [203][204][205] .…”

Synthetic Nitrogen Fertilizers Deplete Soil Nitrogen: A Global Dilemma for Sustainable Cereal Production

“…Agricultural leaching losses of NO 3 − have toxicological implications for animals and humans (e.g., Camargo and Alonso, 2006) and have generated public concern over escalating costs of compliance with municipal water quality standards. For the producer, NO 3 − leaching represents an economic loss, not only of a valuable nutrient, but also of the exchangeable bases that serve as counterions (e.g., Brye and Norman, 2004). The magnitude of this loss on a regional scale has been well documented for the Mississippi River Basin, with an annual average load of approximately 0.86 Tg of NO 3 − –N between 1996 and 2005 (Aulenbach et al, 2007), nearly threefold higher than the average flux between 1956 and 1965 (Goolsby and Battaglin, 2001) and attributed largely to N fertilization (Mississippi River/Gulf of Mexico Watershed Nutrient Task Force, 2008).…”