Dry matter and nutrient accumulation by two maize cultivars with and without supplemental irrigation

Abstract

The objective of this study was to determine possible differences in dry matter, N, P, K, Ca, Mg and Zn accumulation between two maize varieties, BR 105 and BR 126, with and without supplemental sprinkler irrigation, in Sete Lagoas, Minas Gerais, Brazil, At 15, 35, 56, 78, 119 and 140 days after emergence, six plants per replication were harvested for dry master determination and chemical analysis. The plants (above ground) were divided into stem, leaves, husk, cob and grains. Supplemental irrigation increased grain yield in both varieties. Although dry matter accumulation by BR 105 was the same with and without irrigation, lack of supplemental irrigation caused reduction in the nutrients translocation to the grain. For BR 126, both total dry matter accumulation and nutrient translocation to grain were reduced without irrigation. The ratio of nutrient content in the grains over total nutrient absorved was greater for BR 105 than for BR 126, indicating that BR 105 is more efficient. The amount of nutrient exported in the grain are as follows: N (43-93 kg/ha) > > (12-25 kg/ha) > P (11-20 kg/ha) > Mg (4-7 kg/ha) > Ca (0.2-06 kg/ha) > Zn (0.07-0.13 kg/ha). Grain yield ranged from 3,350 kg/ha for 'BR 126' without, to 6,500 kg/ha for 'BR 105' with irrigation.