Nitrate Leaching and Nitrogen Recovery Following Application of Polyolefin‐Coated Urea to Potato

Abstract

High N fertilizer and irrigation amounts applied to potato (Solanum tuberosum L.) on coarse-textured soils often result in nitrate (NO3) leaching and low recovery of applied fertilizer N. This 3-yr study compared the effects of two rates (140 and 280 kg N ha(-1)) of a single polyolefin-coated urea (PCU) application versus split applications of urea on 'Russet Burbank' potato yield and on NO3 leaching and N recovery efficiency (RE) on a loamy sand. Standard irrigation was applied in all years and excessive irrigation was used in another experiment in the third year. At the recommended rate of 280 kg N ha(-1), NO3 leaching during the growing season was 34 to 49% lower with PCU than three applications of urea. Under standard irrigation in the third year, leaching from five applications of urea (280 kg N ha(-1)) was 38% higher than PCU. Under leaching conditions in the first year (> or = 25 mm drainage water in at least one 24-h period) and excessive irrigation in the third year, PCU at 280 kg N ha(-1) improved total and marketable tuber yields by 12 to 19% compared with three applications of urea. Fertilizer N RE estimated by the difference and 15N isotope methods at the 280 kg N ha(-1) rate was, on average, higher with PCU (mean 50%) than urea (mean 43%). Fertilizer N RE values estimated by the isotope method (mean 51%) were greater than those estimated by the difference method (mean 47%). Results from this study indicate that PCU can reduce leaching and improve N recovery and tuber yield during seasons with high leaching.

Use of Five Nitrogen Source and Placement Systems for Improved Nitrogen Management of Irrigated Corn

“…In the current study, greater yield response at the low N rate by banding a mixture of UAN and NF compared with UAN at Concord may be attributed to reduced surface runoff and leaching losses due to high early-season precipitation after N application (Table 1). Zvomuya et al (2003) found that values of NO 3 -N leaching with polymercoated urea ranged from 7 to 62 kg ha −1 , which was 34 to 49% lower than urea.…”

Enhanced Efficiency Fertilizers for Improved Nutrient Management: Potato (Solanum tuberosum)

“…Potatoes have a relatively high cost of production and value, with average expenditures of $1780 to $2690/acre (55). Nearly 20% of operating cost is fertilizer, and potatoes require more than most crops (47,49,57,91). The combination of high fertilizer rates and acreage makes nutrient management an important priority in potato production.…”

“…The consequence of poor efficiency and high water/fertilizer rates in potato is the potential for significant N contamination to surface (23,24,47,49) and groundwater (22,24,41,47,48,49,60,86,91). In addition, nitrous oxide emissions from potato fields are higher than those of most other crops (61,62), which is likely related partially to high fertilizer and water application rates (49).…”

Corn Response to Nitrogen Management under Fully‐Irrigated vs. Water‐Stressed Conditions

“…The use of specialized "controlled-release" N fertilizer sources, including PCU and urea amended with IU, has the potential to minimize NO 3 -leaching (Wilson et al, 2010;Zvomuya et al, 2003) and nitrous oxide emissions (Halvorson et al, 2010;Hyatt et al, 2010). There is some concern, however, about the effectiveness of PCU and IU under dryland conditions because of erratic release rates with fluctuating soil moisture (Fujinuma et al, 2009) and studies showing limited or no effectiveness (Sistani et al, 2011;Venterea et al, 2011).…”