Chemical composition of Panicum maximum ‘BRS Zuri’ subjected to levels of salinity and irrigation depths

Eranildo Brasil Da Silva,Maria Socorro De Souza Carneiro,Rafael Nogueira Furtado,Marcos Neves Lopes,Marilena De Melo Braga

doi:10.5935/1806-6690.20200016

Abstract

The study of cultivars with moderate flood tolerance is essential to their use in pastures irrigated with saline water. The aim of this study was to evaluate the chemical composition of Panicum maximum ‘BRS Zuri’ under the effect of different irrigation depths and levels of salinity. A randomised block design of split plots was used with five replications per treatment. The treatments resulted from the combination of three levels of water salinity (S1 = 0.6, S2 = 1.8 and S3 = 3.0 dS m-1) and four levels of irrigation (I1 = 60%, I2 = 80%, I3 = 100% and I4 = 120% of the evapotranspiration). The chemical composition of the grass, Panicum maximum ‘BRS Zuri’, cut at 28 days, was evaluated over two cycles. There was an interaction between the factors (salinity x irrigation depth x cycle) for the dry matter (DM) content. With the increase in irrigation depth, there was a linear reduction in the crude protein (CP) content in both cycles. The neutral detergent fibre (NDF) and cellulose (CEL) content increased linearly as a function of the irrigation depth, while the lignin (LIG) content decreased linearly with irrigation depth. It was concluded that high levels of salinity cause reductions in the dry matter content in response to increased water availability and extension of the cultivar cycles. The reduction in saline levels under low water availability results in a higher CP content. Salinity has a negative effect on the NDF, ADF, HEM, CEL and LIG content as the irrigation depth increases.

Highlights

The use of pasture as the main source of feed for cattle bred in tropical regions around the world is due to the low cost of production, and is the most economical and practical way of feeding the herd, serving as the basis for cattle farming worldwide (ROJASDOWNING; HARRIGAN; NEJADHASHEMI, 2017)
There was an interaction between the factors for dry matter content (DM)
For the irrigation depth of 60% ET during the first cycle, the greatest DM content was seen at the salinity level of 1.8 dS m-1 compared to the other levels

Summary

Introduction

The use of pasture as the main source of feed for cattle bred in tropical regions around the world is due to the low cost of production, and is the most economical and practical way of feeding the herd, serving as the basis for cattle farming worldwide (ROJASDOWNING; HARRIGAN; NEJADHASHEMI, 2017). Pasture production is most often linked to irrigation systems or water sources that help to reduce losses in production due to drought. A forage grass cultivar that is tolerant to salinity has the adaptive capacity to withstand conditions unfavourable to plant development. As such, their high efficiency in absorbing water in saline environments stimulates their photosynthetic capacity to accumulate a larger amount of dry matter, an important characteristic of tolerant cultivars (SCHOSSLER et al, 2012)

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Results