Dry Matter, Nitrogen, Phosphorus, and Potassium Accumulation Rates by Corn on Norfolk Loamy Sand¹

Abstract

The maximum amount and rate of nutrient accumulation by irrigated corn (Zea mays L.) must be known so that farmers do not waste money or pollute water resources by applying excessive amounts offertilizer. Aerial whole plant samples were therefore collected from irrigated field experiments conducted on Norfolk (Typic Paleudults) loamy sand in t980, t98t, and t982, to determine seasonal dry matter, N, P, and K accumulations for corn yielding tO Mg ha-1 or more in the southeastern Coastal Plain. Rates of accumulation were derived by differentiating compound cubic polynomial equations that described seasonal accumulation patterns. Total dry matter accumulation averaged 23.t and 24.9 Mg ha-1 for two population treatments that averaged 7 X t0 4 or tO X t0 4 plants ha-1 • Aerial N, P, and K accumulation respectively averaged 228, 58, and 258 kg ha-1 in t980; 264, 37, and 372 kg ha-1 in t98t; and 225, 37, and 335 kg ha-1 in t982. Grain yields averaged t3.4, 11.7, and tO.~ Mg ha-1 in t980, t98t, and t982, respectively. Lower P accumulations in t98t and t982 were the result of lower grain yields that were apparently caused by excessive K accumulation. Calculated peak dry matter, N, P, and K accumulation rates were 650, tO, 1.6, and 28 kg ha-1 day-1 in this study, compared to rates of 247, 4.5, 0.6, and 3.2 kg ha-1 , respectively, in previous midwestern studies. Peak accumulation rates during both vegetative and reproductive growth stages emphasize that cultural, nutrient, and water management practices must be coordinated to provide a minimum stress production environment for high corn yield.

Second-crop N fertilization improves lowbush blueberry (Vaccinium angustifolium Ait.) production

“…hybrids tended to respond differently to varying ratios of N and K fertilizers. Some researchers, who observed a decrease in uptake of N by K, suggested that K interferes with or competes with N for uptake (Lueking et al 1983;Karlen et al 1987). Other studies indicate that K and NH 4 + do not compete for uptake (MacKenzie et al 1988;Mengel et al 1976), or that their uptake might be complementary (Dibb and Thompson 1985).…”

Cover Crop-Based, Organic Rotational No-Till Corn and Soybean Production Systems in the Mid-Atlantic United States

“…The timing of N release is critical. If N is released too early, prior to when corn enters its peak N demand phase (at approximately the corn six-leaf stage, V6 [62]), the N is susceptible to environmental loss via leaching and gaseous emissions. If N is released too late, it will not provide appropriate nutrition for the corn crop, negatively affecting corn production.…”

Model for accumulation of dry matter and plant nutrients by corn

“…In all response graphs time is referenced to Jan. 1, which facilitates comparison of various studies on a common time scale, and makes time of year and time of initiation more apparent. Karlen et al (1987) conducted a 3-year experiment at Florence, SC with 'Pioneer 3382' hybrid corn on Norfolk loamy fine sand (fine-loamy, siliceous, thermic Typic Paleudult). Data for 1982 with N-P-K fertilizer rate of 268-36-224 kg ha" 1 and plant population of 70,000 plants ha 1 were used for this analysis.…”