Soil Nitrogen and Phosphorus Behavior in a Long‐Term Fertilization Experiment

Abstract

Accurate fertilizer recommendations rely on quantitative estimation of nutrients supplied by soil and fertilizer nutrients immobilized by soil. Understanding variation in these processes over space and time is critical for site-specifi c nutrient management. Our objective was to characterize spatial variability in N and P cycling for a corn [Zea mays L.]-soybean [Glycine max (L.) Merr.] rotation in southern Minnesota glacial-till soils. Soil samples and grain yield measurements were taken annually from 0.014-ha cells within two 16-ha fi elds. We determined eff ects of fertilizer P additions and crop P removal on soil test phosphorus (STP) and determined relationships between STP changes and soil variables. We also determined temporal stability of soil mineralizable N and inorganic N. Th e spatial patterns of mineralizable N were consistent over time. Th e spatial pattern of soil NO 3 -N was consistent with mineralizable N at a well-drained site, but not at a poorly-drained site. Change in STP per kg P net addition or removal exhibited spatial autocorrelation. Declines in STP under net P removal were directly related to initial STP values. Increases in STP under net P addition were signifi cantly related to pH at both sites and mineralizable N at one site. Temporal stability in mineralizable N suggests that predictive approaches to site-specifi c N management may succeed when the environment for mineralization is uniform. Within-fi eld variability in the relationship between STP and net P addition may substantially aff ect fertilizer P rates required to attain critical STP values and should be accounted for in variable-rate P applications.

Effect of Urea With Nutrisphere-N Polymer in Fall and Spring Nitrogen Applications for Corn

“…Fertilizer recommendations depend on evaluation of supplied and immobilized nutrients in the soil, which are especially important for site-specific management of nutrients (Anthony et al, 2012). Key factors in improving N use efficiency and uptake are nitrification and ammonia volatilization (Mortvedt et al, 1999).…”

Effect of Polymer Seed Coating With Micronutrients on Soybeans in Southeastern Coastal Plains

“…Anthony et al (2012b) noted that fertilizer recommendations rely on estimating nutrients supplied and immobilized in the soil, which is important for sitespecific nutrient management. Micronutrients use in the fertilization program becomes a common practice on farms, but it is important to conduct more studies (Goncalves et al, 2011).…”

Evaluation of Nitrogen Application Methods and Rates With Nutrisphere-N on Soil Nitrate-Nitrogen in Southeastern Coastal Plains

“…Fertilizer recommendations depend on estimating supplied and immobilized nutrients in the soil (Anthony et al, 2012). More applied fertilizers to sustain crop production may lead to environmental issues (Ni et al, 2011) and soil and groundwater Nitrogen (N) pollution, which is a concern for animals and humans (Hubbard et al, 2004).…”