Effects of nitrogen fertilisation and irrigation on seed yield and yield components of signal grass (Urochloa decumbens)

Abstract

The effects of nitrogen (N) fertiliser rate and irrigation on seed yield and its components were evaluated for signal grass (Urochloa decumbens (Stapf) R.D. Webster; syn. of Brachiaria decumbens Stapf) cv. Basilisk in a field experiment in Umuarama, Paraná, Brazil. Two water regimes (irrigated and non-irrigated) and four nitrogen (N) fertiliser rates (0, 25, 50 and 75 kg ha–1) were applied to perennial signal grass crops in a split-plot randomised complete block design with three replications. In two consecutive harvests, favourable rainfall resulted in irrigation having limited influence on most measurements, and the combined application of irrigation and N fertiliser did not improve seed yield. Compared with the nil N, the highest N application rate significantly increased seed yield for the first crop (266 vs 498 kg ha–1) and the second crop (104 vs 286 kg ha–1). Nitrogen fertilisation significantly increased number of seed per area, reproductive tiller density and plant biomass at harvest for the first and second crops. Harvest index, 1000-seed weight, reproductive tiller weight, number of spikelets per panicle and number of seeds per panicle were unaffected by N rate. Harvest index ranged from 1.10% to 3.63% and 1000-seed weight from 2.15 to 3.36 g. There were no treatment effects on number of days to flowering or anthesis. Fertilisation with 75 kg N ha–1 for the first crop and 50–75 kg N ha–1 for the second crop maximised signal grass seed yield.

Effects of Water and Nitrogen Addition on the Seed Yield and Germination Characteristics of the Perennial Grass Leymus chinensis (Trin.) Tzvel

“…The heading number of Zoysia japonica, Agropyron cristatum, and Psathyrostachys juncea increases significantly under a suitable level of N application (Tandoh et al, 2019;Qasim et al, 2020;Zanon et al, 2020). However, our findings are inconsistent with a previous study conducted in Brazil showing that the seed yield of grass was not greatly affected by water (Canto et al, 2020).…”

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

“…The N-rate of 150 kg N/ha produced approximately 16% more TN than the control treatment. Our results were similar to those obtained in previous studies on U. decumbens and U. ruziziensis, which showed that TN increased with an increase in the N-rate [20,21]. Wongsuwan [18] also found that the addition of 150 and 250 kg N/ha significantly increased total reproductive tiller numbers.…”

“…These studies found that the optimal N-rate varied from 40 kg/ha to 400 kg/ha due to several factors, such as soil nutrients, including N, soil moisture, changes in environmental parameters that affect crop development, and other aspects related to crop management. Research groups in different countries have undertaken studies on Urochloa; for example, in Brazil, studies have been conducted on U. brizantha [20] and U. decumbens [21], and in Benin, on U. ruziziensis [22]. Their results showed that N-rates for seed production ranged from 50 kg/ha to 100 kg/ha.…”

Growth and Yield Response of Signal Grass (Brachiaria decumbens Stapf) Applied with Different Rates of Nitrogen Fertilizer

“…Lighter dry matter yields were obtained from the unfertilized plants and those applied with 30 kg N ha -1 . The result is in conformity with the reported increase in plant biomass of signal grass (Canto et al, 2020) and dry matter yield of palisade grass (Dupas et al, 2016) with N fertilization.…”

“…These corroborated the results of Silva et al (2013) who reported an increase in the number of vegetative tillers of marandu grass with N fertilization due to its positive effect on leaf elongation and tillering rate promoting greater capacity in the formation of axiliary buds, which may potentially originate new tillers. Likewise, Canto et al (2020) reported significant increase in reproductive tiller density of signal grass at harvest for the first and second crops with N fertilization.…”