Potential of ground coverage and suppression of purple nutsedge (Cyperus rotundus) by cover crop residues

ABSTRACT

Cover crops have great potential for sustainability of crop production systems. Several studies have been conducted to select the cover crop for using in no-tillage system in the Brazilian Cerrado region. The objective of this experiment was to evaluate the potential as soil cover of millet, dwarf pigeon pea and Crotalaria spectabilisand their effects on the suppression of purple nutsedge (Cyperus rotundus) in the Cerrado region. The experiment was conducted on an Oxisol, having randomized complete block design with four replications. The treatments consisted of species of cover crops i. e. millet, dwarf pigeon pea and Crotalaria spectabilisand fallow. The dry and green fitomass, fitomass decomposition rate and soil cover rate of the cover crops were avaluated. Cover crops were cut and spread on soil surface ninety days after emergence and the evaluation of the density of purple nutsedge were done at 30, 60, 90 and 120 days after cutting(DAC). The millet showed the highest dry fitomass, 12.71 Mg ha^-1. The dwarf pigeon pea residue showed lower decomposition rate. The densityof purple nutsedge at 120 DAC was 56.1%; 40.6% and 30.3% for millet, dwarf pigeon pea and Crotalariaspectabiliscompared to fallow.

Key words:
biomass production; decomposition rate; no-tillage; sustainable management; weed