Corn Residue and Nitrogen Source Effects on Nitrogen Availability in No-Till Corn

摘要: Effective N management practices are needed in high residue corn (Zea mays L.) production systems to enhance fertilizer efficiency and avoid yield reductions due inadequate supplies. This 4-yr study was conducted on a well-drained silt loam soil southern Wisconsin (43°17' N, 89°22' E) determine the effects of cover amounts supplying capability, effectiveness several surface-applied fertilizers, relative importance mechanisms potentially contributing reduced no-till systems. Treatments consisted level [none (Ox), normal (1 x), twice (2x), artificial (polypropylene) (AR1x)], source (ammonium nitrate, urea, urea-ammonium nitrate solution), rate (0-225 kg ha-1 45-kg increments). Increasing levels lowered temperatures early season NO 3 -N production, grain yields without applied N. Ammonia losses urea-containing fertilizers but did not completely explain observed differences. Nitrogen were similar at all levels, suggesting that added can overcome levels. Yields, mineralization, soiltemperature 1x AR1x treatments,indicating temperature rather than immobilization is main contributor decreased higher Differences difference mean requirement Ox suggest applying about 30 extra will provide benefits some years