Nitrogen management of forage grasses for nutrition, seed production, and nutrients in residual straw

Abstract

The objective of this work was to evaluate the nutrition, accumulation of nutrients in residual straw, pure seed yield, and seed quality of the tropical forage grasses 'Mombaça' and 'Xaraés' subjected to topdressing with nitrogen fertilizer management. Field experiments were carried out in the municipalities of Rancharia and Presidente Prudente, in the state of São Paulo, Brazil. The treatments included a control (without N topdressing) and four N fractionation forms at different forage stages: 150 kg ha-1 N, at the vegetative phase (VP); 150 kg ha-1 N, at the beginning of the reproductive phase (RP), between panicle initiation and the prebooting stages; 100 kg ha-1 N, at VP plus 50 kg ha-1 N at RP; and 50 kg ha-1 N at VP plus 100 kg ha-1 N at RP. Fertilization with N as topdressing, regardless of the N fractionation form, increased N concentration in the flag leaf and in residual straw, and the quantities of N accumulated by 'Mombaça' and 'Xaraés' forage grasses. The application of all or most N in the VP increased the quantities of residual straw and of P and K accumulated by the 'Mombaça' forage grasses. The application of all or most N in the RP provided a greater pure seed yield and N use efficiency in both forage grasses. The seed physiological quality of the forages is not affected by fertilization with N topdressing.

Effects of Closing Cut Date and Nitrogen Fertilization on Seed Yield and Seed Quality in Two Novel Cultivars of Urochloa spp.

“…Moreover, N fertilization management can affect the seed yield and quality of tropical forage grasses. The responses of tropical grasses as a function of N fertilization management may vary between species and cultivars [39]. Additionally, in terms of economic performance and the relationship between seed production and N-rate, the results of this study showed that no N fertilizer was appropriate for the two novel Urochloa cultivars in northern Thailand.…”

“…We have found that many tillers become yellowish from the start of seed harvest until the end of harvest. Furthermore, previous studies have shown that a split N application can improve nutrient use efficiency, promote optimal seed yields, and reduce nutrient loss [39,40]. Therefore, to achieve high seed yields in the two novel Urochloa cultivars, besides N fertilizer application after closing cut, applying N before flowering may be required.…”

Intercropping sorghum and grasses during off-season in Brazilian Cerrado

“…Off-season dry mass production for sole palisade grass was 3,920 kg ha -1 (Table 2). According to Catuchi et al (2019), the high amounts of dry mass produced by this species are very useful for straw production for no-till purposes. Even when grown during the dry season or under partially shaded conditions -such as intercropping systems -palisade grass produced 3,884 kg ha -1 and 2,709 kg ha -1 of dry matter at 0.5 and 0.7 m row spacing's respectively (Table 2), thus confirming its adaptability to intercropping systems at early growth stages (Santos et al, 2018b).…”

“…Rich). R. D. Webster) is commonly used in intercropping systems, due to its superior adaptability to shaded conditions in early growth stages (Santos et al, 2018a), and to its high dry matter production (Catuchi et al, 2019). Congo grass (Urochloa ruziziensis (R. Germ.…”

Sequential cutting of Urochloa brizantha cv. MG 5 changes flowering season and seed production components

“…The management programs of tropical forage grasses in Brazil aimed to increase the development of vegetative structures (vegetative tillers and leaves), with a particular focus on pasture (BARCELOS et al, 2011;CECATO et al, 2014). However, for the production of seeds, the development of reproductive structures (reproductive tillers, flowers, and seeds) should be prioritized, which has led to questions about the proper management of forage plants (NERY et al, 2012;CATUCHI et al, 2013;2019).…”