Soil nutrient stratification and uptake by wheat after seven years of conventional and zero tillage in the Northern Grain belt of Canada

Abstract

Soil nutrient stratification and uptake by wheat after seven years of conventional and zero tillage in the Northern Grain belt of Canada. Can. J. Soil Sci. 86: 767-778. The distribution of NaHCO 3 -extractable nitrate-N, ammonium-N, phosphorus (P) and potassium (K) with soil depth (0 to 20 cm in 5-cm increments) at Fort Vermilion (58°23′N 116°02′W), Alberta, was described in the 7th and 8th years of conventional and zero tillage following placement of red clover (Trifolium pratense) green manure (GM), field pea (Pisum sativum), canola (Brassica rapa) and monoculture wheat (Triticum aestivum) residues. Soil nitrate-N concentrations under zero tillage were greater than those under conventional tillage in the 0-5 cm soil layer, below which the concentrations were similar. Ammonium-N and K concentrations followed a similar pattern. However, soil P concentrations were usually not different between tillage systems in the 0-5 cm soil layer, but the concentrations decreased more under zero tillage than under conventional tillage at lower depths. A notable exception for soil phosphate was under canola residues, where the concentration was greater under zero tillage than under conventional tillage at all depths. Uptake of N, P or K by a subsequent wheat crop was usually greater (though not always significantly) under zero tillage than under conventional tillage, and there were no interactions between tillage and crop residue. Therefore, differences in nutrient stratification between the two tillage systems did not translate into differences in wheat nutrient uptake. (58°23′N; 116°02′O), en Alberta, la septième et la huitième année d'un régime de travail ordinaire et de non-travail du sol après incorporation d'un engrais vert de trèfle rouge (Trifolium pratense) ou des résidus de pois de plein champ (Pisum sativum), de canola (Brassica rapa) et de monoculture du blé (Triticum aestivum). La concentration de N-nitrate est plus importante sans travail du sol que lorsque le sol est travaillé de la façon usuelle dans la couche de 0 à 5 cm de profondeur, en dessous laquelle les concentrations sont similaires. La concentration de N-ammonium et celle de K présentent des tendances analogues. La concentration de P ne varie généralement pas avec le type de travail du sol dans la couche de 0 à 5 cm, mais à une profondeur supérieure, elle diminue davantage quand le sol est travaillé. Les résidus de canola se distinguent du reste en ce sens que la concentration de phosphate dans le sol est plus élevée lorsque le sol reste intact et ce, à toutes les profondeurs. L'absorption du N, du P ou du K par le blé cultivé subséquemment est habituellement plus importante (mais pas toujours de manière significative) avec le non-travail du sol, comparativement au travail du sol, mais il n'existe pas d'interaction entre le régime de travail du sol et les résidus végétaux. Par conséquent, la variation de la stratification des éléments nutritifs entre les deux régimes ne fait pas fluctuer l'absorption des éléments nutritifs par le blé.

Nongrowing season soil surface nitrate and phosphate dynamics in a corn–soybean rotation in eastern Canada: in situ evaluation using anionic exchange membranes

“…Previous studies conducted in Canada reported that fertilized NT had a greater soil mineral N and extractable P in the top 5 cm layer and to some extent down to 10 cm, and a depletion of N and P in sublayers; however, soil mineral N and extractable P uniformly distributed down to 20 cm under moldboard plow (MP) (Lupwayi et al 2006;Cade-Menun et al 2010;Messiga et al 2012). These findings indicated that soil depth at 0-5 cm under NT can be the most active layer for potential N and P losses.…”

“…Agricultural practices, including tillage, fertilization, and crop rotation, could affect the transformation and movement of soil N and P. Studies have shown that notill (NT) management has caused the stratification of soil organic carbon (Zibilske et al 2002), nitrate (Grant and Lafond 1994;Lupwayi et al 2006), and extractable P (Cade-Menun et al 2010;Messiga et al 2012;Abdi et al 2014). Previous studies conducted in Canada reported that fertilized NT had a greater soil mineral N and extractable P in the top 5 cm layer and to some extent down to 10 cm, and a depletion of N and P in sublayers; however, soil mineral N and extractable P uniformly distributed down to 20 cm under moldboard plow (MP) (Lupwayi et al 2006;Cade-Menun et al 2010;Messiga et al 2012).…”

Decimetric‐Scale Two‐Dimensional Distribution of Soil Phosphorus after 20 Years of Tillage Management and Maintenance Phosphorus Fertilization

“…This gradient of P concentration is due in part to year-to-year broadcast or band application of P fertilizer at or near the same sowing row, to the absence of mixing of P fertilizers with soil and crop residues left on the soil surface after harvest, and to the subsequent leaching of P from crop residues (Duiker and Beegle, 2006). Phosphorus stratification has implications for crop nutrition, since P depletion in the rooting zone, where P is needed by plant roots, may reduce crop yield (Lupwayi et al, 2006). Several strategies have been suggested to address this issue, including strategic tillage (Dang et al, 2015) and the collection of separate soil samples from different layers to capture the vertical variability found in the rooting zone and thus ensure better fertilizer P recommendations and placement methods (Cade-Menun et al, 2010).…”

Effects of Short-term Tillage of a Long-term No-Till Land on Available N and P in Two Contrasting Soil Types

“…Previous research under long-term no-tillage (NT) management has shown higher amounts of available P in the surface thin layer (0 to 5 cm or less) under NT than CT (Eckert 1985;Weil et al, 1988;Karlen, 1991;Ismail et al, 1994;Selles et al, 1997;Selles et al, 1999;Lupwayi et al, 2006, Mathers & Nash, 2009, Cade-Menun et al, 2010. Similarly, in our study, the amounts of extractable P in the surface 0-7.5 cm soil layer were greater under NT compared to RT, but the amounts of extractable P in the 7.5-15 and 15-20 cm layers were greater with RT compared to NT.…”