Irrigated Corn Yield and Nitrogen Accumulation Response in a Comparison of No‐till and Conventional Till: Tillage and Surface‐Residue Variables

Abstract

Comparisons between no‐till and conventional‐till management are often confounded by variation in both tillage and residue placement. The objective of this research was to separate the tillage variable from the surface‐residue variable associated with no‐till and conventional‐till management comparisons in irrigated continuous corn (Zea mays L.) production. Two Nebraska locations (Mead and Clay Center) with differences in soil types and climate were selected. Four tillage‐residue treatments [NT‐NR (no‐till, residue removed), NT‐R (no‐till, surface residue), T‐NR (till, residue removed), T‐R (conventional till, surface residue)] were fertilized by either broadcasting at planting or sidedressing at the 6‐leaf stage with rates of 0, 56, 112, and 168 kg N ha−1. At Clay Center, grain yields and total N accumulation were similar for all tillage‐residue treatment combinations in all years when the highest fertilizer N rate was used. In 2 of 3 yr at Mead, grain yields and total N accumulation were less for no‐till than conventionaltill treatments, but in 1 yr the yields and total N accumulations were greater in no‐till than conventional‐till treatments. At Mead, surface residue resulted in lower grain yields and total N accumulation compared with bare soil at lower N rates, but not at greater N rates, in 2 of 3 yr. Sidedressing fertilizer N was generally a more efficient N placement than broadcasting. Differences between tillage and residue effects at Clay Center and residue effects at Mead were overcome with higher rates of fertilizer N. Tillage effects at Mead did not appear to be N‐related. The data suggest that tillage may be necessary to maintain optimum production levels on finer‐textured soils when spring soil temperatures are cool and slow to warm. When spring soil temperatures are warm, no‐till strategies can be used for optimum production levels on these soils.

Growth, Phenology and Seed Yield of Fodder Maize in Relation to Different Planting Methods and Nitrogen Levels

“…Method of sowing is the major factor which is responsible for soil moisture storage, judicious use of fertilizer, water, good crop stand and better crop growth. Simes et al, (1998) suggested that pre-plant tillage may be necessary to optimize grain yield and reported lower continuous corn yields with no tillage compared with conventional tillage. The conventional flat planting is the common practice of raising crops in India but this practice has resulted in the degradation and inefficient use of basic resources and various inputs.…”

Diagnose foliar em plantas de milho em sistema de semeadura direta em função de doses e épocas de aplicação de nitrogênio

“…Segundo MAR et al (2003), para se obter a máxima eficiência do fertilizante nitrogenado é importante determinar as épocas em que esse nutriente é mais exigido pelas plantas, permitindo assim, corrigir as deficiências que possam ocorrer no desenvolvimento da cultura. A eficiência da adubação Nascimento et al (2012) nitrogenada é dependente de condições climáticas, tipo de solo, acidez, conteúdo de argila, cultivares, cultura antecessora, distribuição de chuvas, níveis de fertilização nitrogenada e sua interação com outros nutrientes (SIMS et al, 1998).…”

Lixiviação e imobilização de nitrogênio num nitossolo como variáveis da forma de aplicação da uréia e da palha de aveia

“…Verifica-se que, quando as doses de N adicionadas são maiores que a necessidade das culturas, o rendimento vegetal não tem sido afetado pelo método de aplicação ou pela presença ou não de palha (Sims et al, 1998) porque as perdas de N, nesse caso, são inferiores ao excesso disponível.…”

“…Sendo assim, as recomendações de fertilização nitrogenada são baseadas em experimentos regionais, cujas respostas variam com o pH, quantidade de matéria orgânica (CFS/RS-SC, 1995), tipo de preparo (Sims et al, 1998) e características químicas do solo (Howard & Essington, 1998), além do manejo da cobertura vegetal morta (Sims et al, 1998;Vaughan & Evanylo, 1998), do tipo (Aulakh et al, 2000, da época (Basso & Ceretta, 2000) e da forma de aplicação dos fertilizantes nitrogenados (Howard & Essigton, 1998;Sims et al, 1998).…”