Root growth and yield of sugarcane as a function of increasing gypsum doses

Abstract

Sugarcane plays an important role in the Brazilian agribusiness. However, poor rainfall distribution and soil acidity directly affect its production in the Northeast Brazil. Gypsum improves the soil physical and chemical properties, attenuating the effects of water stress and acidity in the edaphic environment. This study aimed at determining the effect of gypsum doses on sugarcane growth and yield. A field experiment was conducted using a 3 x 5 factorial arrangement organized in a randomized block design, with four replications. Treatments consisted of a combination of three sugarcane varieties (RB011941, RB92579 and RB991536) with five gypsum doses (0 Mg ha-1, 2.5 Mg ha-1, 5.0 Mg ha-1, 10.0 Mg ha-1 and 20.0 Mg ha-1). RB92579 exhibited the highest stalk (157.90 Mg ha-1) and sugar (24.10 Mg ha-1) yield. Gypsum did not influence the sugarcane yield or plant growth in the vegetative growth stage, but, in the maturation phase, the leaf area declined and the number of shoots increased with the rise in gypsum doses. Applying gypsum increased the roots density along the soil profile, with a rise of around 1.10 g dm-3 at the most technically efficient dose (12.5 Mg ha-1), however, yield was not influenced, maybe due to the effect of high rainfall during the entire crop cycle. Thus, higher gypsum doses are recommended during periods of drought to benefit from the resulting increased root system.

Nutritional status and technological quality of sugarcane due to increasing gypsum doses

“…In recent years, it has gained global interest as a raw material for the production of biofuels, since its energy balance is potentially positive (Smeets et al, 2009;Losordo et al, 2016). In the global scenario, Brazil stands out as the largest producer, whose production system is one of the most competitive in the world, mainly due to the development of national science and technology for the production of sugarcane, extraction and industrialization of the juice, use of sugar-alcohol waste in the fertilization of cane fields, and electric power generation (Clemente et al, 2017;Oliveira et al, 2017;Pereira et al, 2017). Despite the promising scenario, currently, the sugarcane crop faces a serious agricultural and industrial crisis, marked by low yields of sugarcane plantations, especially in northeastern Brazil.…”

“…For example, the state of Alagoas, which is the largest producer in the region, has an average stem yield of less than 60 t ha -1 , well below the biological potential of the crop (Silva et al, 2017b). The low yields in the Northeast are mainly related to the irregular seasonal distribution of rainfall (Oliveira et al, 2011a;Abreu et al, 2013;Silva et al, 2014) and marked acidity in soils (Clemente et al, 2017). In coastal tablelands, water deficiency occurs in spring-summer (Souza et al, 2004), which results in a lack of water during most of the plant growth period.…”

“…Among the various agronomic practices being used to mitigate the effect of water deficit in plants, the use of gypsum deserves highlight. Gypsum improves root distribution in depth and allows plants to use larger volumes of water and nutrients, especially during drought periods (Souza et al, 2007;Clemente et al, 2017). Several researchers report that gypsum provides root deepening, resulting in an increase in stem yield (Morelli et al, 1992;Rocha et al, 2008) and sugars (Clemente et al, 2017), which may be related to improvement of the nutritional status and technological quality of sugarcane.…”

“…Gypsum improves root distribution in depth and allows plants to use larger volumes of water and nutrients, especially during drought periods (Souza et al, 2007;Clemente et al, 2017). Several researchers report that gypsum provides root deepening, resulting in an increase in stem yield (Morelli et al, 1992;Rocha et al, 2008) and sugars (Clemente et al, 2017), which may be related to improvement of the nutritional status and technological quality of sugarcane. In view of the above, the aim of this study was to evaluate the nutritional status, photochemical efficiency, and technological quality of three sugarcane genotypes subjected to increasing doses of mineral gypsum.…”

Avaliação do efeito do nitrogênio e do silício na produtividade da água em biomassa e energia da cana-de-açúcar (<i>Saccharum spp.</i>)

“…Em relação à valor médio da altura da planta foi de 2,95 m (Tabela 9), estes resultados foram semelhantes aos obtidos por Aquino et al (2017) para a soca da variedade SP801816, em sequeiro na região sudeste com 3,00m; para a soca da variedade RB92579, no nordeste condições de sequeiro Costa et al (2011) reportaram 2,75 m. Por outro lados, os resultados foram superior aos encontrados em condições de estresse hídrico por Silva et al (2008) em 80 variedades de 1,93 m e em 12 famílias por Silva et al (2008) com 2,00 m, por sua vez Uribe et al (2013) no sudeste, reportou na soca da variedade SP803280, irrigada com aplicação de 70 kg ha -1 de nitrogênio, uma altura de 1,78m; Chaves et al (2013) no nordeste usando a variedade SP791011 irrigada plenamente com aplicação de 600 kg ha -1 de silício, obteve valores de 1,32 m. Já para a variedade RB92579 Silva (2015) em sequeiro no nordeste aos 270 dias obtêm uma altura de 1,80 m. Entretanto vários autores reportam valores superiores aos 3,00 m para a variedade RB92579 irrigada, assim Oliveira (2008), Oliveira et al (2010) e Silva et al (2012), reportaram alturas de 3,40 m, 3,11 m e 4,00 m respetivamente na região nordeste. Nesta regiãoClemente et al (2017), usando emendas de gesso para a mesma variedade em cana planta observaram uma altura de 2,90 m. Em geral os valores de altura para a variedade RB92579, dependendo das condições de manejo podem variar entre 1,80 m e 4,00 m, neste estudo os resultados encontram-se dentro desta faixa de valores. O volume total do colmo por ser uma variável derivada das duas supramencionadas sua média foi de 1183,24 cm 3 .…”