Quantitative Evaluation of Soil Reaction and Base Status Changes Resulting from Field Application of Residually Acid-Forming Nitrogen Fertilizers

Abstract

An evaluation was made of the changes in soil reaction and exchangeable base content of two Red‐Yellow Podzolic soils and one alluvial soil resulting from high rates of application of ammonium nitrate and of ammonium sulfate. Severe reductions in exchangeable base level and lowering of soil pH occurred within a year after beginning N applications. The undesirable effects occurred deep in the soil profile where corrections would be difficult, if not impossible, from a practical standpoint. Exchangeable K was lost from the soil faster than other bases at the higher rates of N. No indication of a subsoil zone of accumulation of bases leached out of upper horizons was observed. The measured losses of exchangeable bases were appreciably lower than calculated CaCO3 equivalents of the residual acidity of the fertilizer except for the higher N rates on the Toa clay loam.

Improvement in nitrogen availability, nitrogen uptake and growth of aerobic rice following soil acidification

“…Long‐term inputs of N fertilizer to aerobic soil generally reduce soil pH because of the conversion of ammonium to nitrate via nitrification and subsequent leaching of nitrate from the root zone (Abruna et al. 1958; Schwab et al.…”

“…Among the possible factors contributing to the negative yield trend in IRRI's LTE was a prominent increase in soil pH, which rose from 6.4 at the outset of the experiment to nearly 7.1 after 13 seasons of aerobic cultivation. Under aerobic conditions the application of N fertilizers generally reduces the soil pH over time via nitrification and the subsequent leaching of nitrate from the root zone (Abruna et al 1958;Schwab et al 1990). How-ever, at the IRRI site the prolonged use of alkaline irrigation water (pH 8.1) has counteracted the expected acidifying affects of the urea fertilizer used throughout the study.…”

Long-Term N Rates and Subsequent Lime Application Effects on Macroelements Concentration in Soil and in Bromegrass Hay

“…The quadratic regression for 0-5 cm soil layer had a negative linear coefficient and a positive quadratic coefficient, indicating a decline in the concentration at lower N rates followed by an increase in the concentration at higher N rates. But for the deeper soil layers, the quadratic regressions had a positive linear and a negative quadratic coefficient, suggesting an initial increase in their concentrations up to a certain N rate and then a decline with further additions of N. A decrease in soil Ca levels with increasing N rates was observed in earlier studies (Abruna and Elkins 1958;Walcott et al 1965;Schwab et al 1990). Calcium from the exchange sites was apparently replaced by H and Al due to the increased soil acidity and by NH 4 from the added fertilizer.…”

“…Liming has been shown to ameliorate naturally-occurring acid soils and improve their crop yield potential (Hoyt et al 1974;Malhi et al 1995;Arshad and Gill 1996), thus improving the sustainability of crop production on acid soils. Application of N fertilizers to grassland soils has been shown to increase available P (Smika et al 1961;Malhi et al 1992) and decrease exchangeable bases in the soil (Abruna and Elkins 1958;Walcott et al 1965;Schwab et al 1990). There is information on the effects of the long-term N use on some chemical properties of a Gray Luvisolic soil (McCoy and Webster 1977) and a Solonetzic soil (Cairns 1971) in Alberta but information regarding long-term effects of N addition on the concentration of macroelements in Black Chernozemic soils is lacking.…”

Impact of a New Deep Vertical Lime Placement Practice on Corn and Soybean Production in Conservation Tillage Systems

“…Acidic conditions in the subsoil horizons have been shown to affect nutrient availability and root growth of many agronomic crops [2,8,9]. Furthermore, soils under intense cropping systems may have substantial increases in subsoil acidity with depth [10,11].…”