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Residual phosphorus from single and repeated bands in no-till systems as evaluated by crop response and sampling strategies
Abstract
Two sites were established in eastern Nebraska in 1988 to evaluate the effect of knifed in P to a depth of 15 cm in no-till cropping systems on soil residual P as measured by crop yield parameters and soil analysis. Corn (Zea mays L.) was grown for 3 yr, oat (Avena sativa L.) 1 yr on Nora-Crofton sicl (Typic Ustorthents, fine silty, mixed (calcareous), mesic and Udic Haplustolls, fine-silty, mixed, mesic). Wheat (Triticum aestivum L.) was grown for 3 yr, sorghum (Sorghum bicolor (L.) Moench) 1 yr on Sharpsburg sicl (typic Argiudolls, fine montmorillonitic, mesic). Four rates of P, 10 to 40 and 7.5 to 30 kg P ha$\sp{-1}$ were applied on Nora-Crofton and Sharpsburg soils, respectively. Knifed bands were applied 1 to 4 yr as single and repeated bands replicated four times in a factorial treatment arrangement in a randomized complete block design. Plant P and total P uptake increased consistently by applied P in different years. Yield was less consistent on Nora-Crofton soil. The bands' half life as determined by grain yield, was less than a yr to two yr on corn and 1.3 to 1.8 yr on oat when P was applied at 10 and 40 kg P ha$\sp{-1}$, respectively. On the Sharpsburg soil, half life was less than a yr to 2.6 yr on wheat and 1.5 to 4.4 yr on sorghum when P was applied at 7.5 and 30 kg P ha$\sp{-1}$, respectively. The effect of P bands was more persistent with total P uptake than grain yield. Half life on P bands as determined from soil analysis were similar to that predicted by yield and P uptake with lower absolute values. Residual P from previous bands affected the method and the sampling intensity to estimate soil P content. At 30 kg P ha$\sp{-1}$, soil P variability associated with random sampling was 11 times higher than contiguous sampling.
Subject Area
Agronomy|Soil sciences|Biogeochemistry
Recommended Citation
Zerkoune, Mohammed Arezki, "Residual phosphorus from single and repeated bands in no-till systems as evaluated by crop response and sampling strategies" (1996). ETD collection for University of Nebraska-Lincoln. AAI9628257.
https://digitalcommons.unl.edu/dissertations/AAI9628257