Nitrogen fertilization of self-seeding Italian ryegrass: effects on plant structure, forage and seed yield

Autor: Alberto Bohn, Gabriel Streck Bortolin, César Iván Suárez Castellanos, Bruna Barreto dos Reis, Anna dos Santos Suñé, Joice Fernanda Lübke Bonow, Carlos Eduardo da Silva Pedroso, Andréa Mittelmann
Jazyk: English<br />Portuguese
Předmět:
Zdroj: Ciência Rural, Vol 50, Iss 6
Druh dokumentu: article
ISSN: 0103-8478
1678-4596
DOI: 10.1590/0103-8478cr20190510
Popis: ABSTRACT: This study aimed to evaluate the effect of different levels of self-seeding Italian ryegrass (Lolium multiflorum Lam.) and nitrogen rates - applied additionally after two defoliations - on plant structure, in forage and seed yield. Levels of self-seeding were classified as very high (777 kg ha-1), high (736 kg ha-1), intermediate (624 kg ha-1), and low (234 kg ha-1). Populations were fertilized with zero, 20.25, 40.50, and 60.75 kg ha-1 of supplemental nitrogen applied after two defoliations; respectively, in very high, high, intermediate, and low levels. Higher levels of self-seeding promoted greater forage yield and uniformity of vegetation structure. Number of fertile tillers and number of seeds per plant have benefited by the combination of high self-seeding and supplemental nitrogen fertilization. Despite influencing the uniformity and amount of forage obtained in two defoliations, the very high and low self-seeding levels did not differ in Italian ryegrass seed production. However, linear addition for this same variable was obtained with the inclusion of supplemental nitrogen fertilization. In pastures from low and intermediate self-seeding levels, total dry mass increases linearly with the levels of nitrogen fertilization assessed in this research.
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