Cover plants in second crop: nutrients in straw and cotton yield in succession

Abstract

The cultivation of cover plants is a strategy for improving the agricultural production environment and providing straw for soil cover in the no-tillage system, in addition to cycling and providing nutrients to succeeding crops. This study aimed to assess the dry matter yield and nutrients accumulation by cover plants grown alone or intercropped in the second crop after soybean and their effects on cotton grown in succession. The treatments were: Urochloa ruziziensis; Pennisetum glaucum (millet); Zea mays (corn); Crotalaria spectabilis; Crotalaria ochroleuca; Cajanus cajan (pigeon pea); corn + U. ruziziensis; C. spectabilis + U. ruziziensis; C. ochroleuca + U. ruziziensis; pigeon pea + U. ruziziensis; corn + C. spectabilis; corn + C. ochroleuca; and corn + pigeon pea. The experimental design consisted of randomized blocks, with four replications, and the experiment was carried out in two crop seasons. In the cotton pre-seeding, the maximum amount of corn straw dry matter was 2,699 kg ha-1, with low macronutrient contents. The pigeon pea intercropped with U. ruziziensis produced between 8,400 and 12,941 kg ha-1 of dry matter, with a maximum content of 223 and 323 kg ha-1 of nitrogen and potassium, respectively. The U. ruziziensis, grown alone or intercropped, provided between 140 and 323 kg ha-1 of potassium in the straw. A high yield is obtained by cotton grown in the no-tillage system in succession to C. spectabilis.

KEYWORDS: Urochloa ruziziensis, Gossypium hirsutum L., green manures, no-tillage system.