Stalk and sucrose yield in response to nitrogen fertilization of sugarcane under reduced tillage

Abstract

-The objective of this work was to evaluate the agroindustrial production of sugarcane (millable stalks and sucrose yield) after successive nitrogen fertilizations of plant cane and ratoons in a reduced tillage system. The experiment was carried out at Jaboticabal, SP, Brazil, on a Rhodic Eutrustox soil, during four consecutive crop cycles (March 2005 to July 2009). Plant cane treatments consisted of N-urea levels (control, 40, 80, and 120 kg ha -1 N + 120 kg ha -1 P 2 O 5 and K 2 O in furrow application). In the first and second ratoons, the plant cane plots were subdivided in N-ammonium nitrate treatments (control, 50, 100, and 150 kg ha -1 N + 150 kg ha -1 K 2 O as top dressing over rows). In the third ratoon, N fertilization was leveled to 100 kg ha -1 in all plots, including controls, to detect residual effects of previous fertilizations on the last crop's cycle. Sugarcane ratoon was mechanically harvested. A weighing truck was used to evaluate stalk yield (TCH), and samples were collected in the field for analysis of sugar content (TSH). Increasing N doses and meteorological conditions promote significant responses in TCH and TSH in cane plant and ratoons, in the average and accumulated yield of the consecutive crop cycles.Index terms: Saccharum, agroindustrial production, biomass, crop residues, subsoiling, unburned cane. Produtividade de colmo e sacarose em resposta à adubação nitrogenada da cana-de-açúcar, sob preparo reduzidoResumo -O objetivo deste trabalho foi avaliar a produtividade agroindustrial de cana-de-açúcar (produtividades de colmos e sacarose) após sucessivas adubações nitrogenadas de cana-planta e soqueiras, em sistema de preparo reduzido. O experimento foi conduzido em Jaboticabal, SP, em um Latossolo Vermelho eutrófico durante quatro ciclos agrícolas consecutivos (março de 2005 a julho de 2009). Os tratamentos de cana-planta consistiram de doses de N-ureia (controle, 40, 80 e 120 kg ha -1 de N + 120 kg ha -1 de P 2 O 5 e K 2 O no sulco de plantio). Na primeira e na segunda soqueiras, as parcelas de cana-planta foram subdivididas em tratamentos de N-nitrato de amônio (controle, 50, 100 e 150 kg ha -1 de N + 150 kg ha -1 de K 2 O, sobre as fileiras de cana). Na terceira soqueira, a adubação com N foi de 100 kg ha -1 em todas as parcelas, inclusive nos controles, para detectar efeitos residuais das fertilizações anteriores na produtividade do último ciclo. Os colmos de cana foram colhidos mecanicamente. Utilizou-se caminhão instrumentado com balança para avaliação da produtividade de colmos (TCH), e amostras retiradas no campo para análise da quantidade de açúcar dos colmos (TSH). As doses crescentes de N e as condições meteorológicas proporcionam respostas significativas na TCH e na TSH da cana-planta e das soqueiras, na média e na produção acumulada dos ciclos agrícolas consecutivos.Termos para indexação: Saccharum, produtividade agroindustrial, biomassa, resíduos culturais, subsolagem, cana crua.

Yield of sugarcane submitted to nitrogen fertilization and water depths by subsurface drip irrigation

“…The fact that there was no effect of N application, especially in the plant cane cycle, was possibly due to the high content of organic matter in the soil used in the study (Table 1). The response of the plant cane to N is little expressive and normally occurs at low doses (Franco et al, 2010;Fortes et al, 2013).…”

“…Nitrogen (N) fertilization can also promote yield increment in the plant cane cycle (Franco et al, 2010;Fortes et al, 2013); however, the responses to N application are still controversial. Localized irrigation, therefore, may present itself as an alternative, in which water and fertilizers are simultaneously applied through the drip system, promoting reduction in the consumption of water and fertilizers, which may result in higher sugarcane productions (Esperancini et al, 2015).…”

Agronomic performance of green cane fertilized with ammonium sulfate in a coastal tableland soil

“…and lacking reports on S deficiency symptoms. Other studies, such as Prado and Pancelli (2008), Franco et al (2010), and Fortes et al (2013), using different types of N fertilizers, reported cane yield responses to N fertilization that fit to a quadratic function, but linear responses or the absence of response to N fertilization were also reported depending on locality and ratoon cycle. There is little biological basis to select a model over another to describe the crop response to N fertilization (Mead and Pike 1975).…”

“…Nitrogen is usually a limiting nutrient to crop yield in the weathered tropical soils, and positive yield responses to N fertilization are observed for sugarcane in Brazil (Dourado Neto et al 2010;Fortes et al 2013), although less frequently to plant cane (first cycle) owing to higher contribution from N in soil and residue due to N mineralization, as well as the biological nitrogen fixation (Balasubramanian et al 2004;Urquiaga et al 2012;Otto et al 2016). A review on sugarcane pointed out the relatively low N use efficiency (NUE) by the crop, which averages 26% from a range of 7 to 40% of the N fertilizer applied.…”

“…However, such situation is not always observed, as the increase in stalk yield as a function of N fertilization generally offsets the Pol reduction bringing about gains in sugar yield (Franco et al 2010;Fortes et al 2013). Also, the excess of N may have potential deleterious off-set impacts to the environment (Martinelli and Filoso 2008), which makes essential to investigate the N rate for improving the efficiency of this nutrient taken up by the plants.…”