Evaluating Nitrogen Behavior in Sugarcane after Fertilization Using Leaf and Sap Extract Analyzes

Abstract

Nitrogen (N) fertilization is important for sugarcane crops, for both agronomic and environmental reasons. Better use of N from fertilizer is required for crop management, and in order to achieve it, adequate N nutrition monitoring is necessary. Sap extract analysis is a sensitive technique that has been adopted in other crops to tackle this objective, and can be used for sugarcane. The aim of this study was to evaluate the behavior of N and the response of sugarcane after N fertilization, using sap and leaf tissue analysis. The study was undertaken in two experimental areas in 2012/2013 season, using ratoon cane, following application of 0, 50, 100, and 150 kg•ha −1 of N. The youngest visible leaves were sampled from sugarcane at five time points between 0 and 150 days after fertilization, to evaluate the nitrate, ammonium, and total N content of sap extract, and total N content of leaf tissue. At the first sampling point (30 days after N fertilizer application), mineral N in sap increased as a result of N fertilization in medium-textured soil, and remained high until 120 days after fertilization in clayey soil. The total N content of sap followed a similar behavior. Stalk yield was only observed to increase in sugarcane grown in the clayey soil. Sap analysis proved to be an efficient method for monitoring N status in sugarcane grown in different soil types.

Sap Analysis: A Powerful Tool for Monitoring Plant Nutrition

“…Most authors have used petioles as the sampled tissue, usually taking the petioles from the most recent fully expanded leaf [2,19,[28][29][30]34,40,53,54]. Instead of using petioles, in [55] and [56], the leaf blade midribs were used for sap analysis in broccoli (Brassica oleracea) and sugar cane (Saccharum officinarum), respectively, while in [52], the use of leaf blade vs. petioles was compared for sap analysis in strawberries (Fragaria × ananassa). In [57][58][59], leaf blades for sap analysis was recommended, which is becoming an interesting adaptation of the method by private companies in the Netherlands [19].…”

“…Few authors have followed this approach of collecting old and new growth [58]. Most of the published work related to sap analysis has been focused on N and mostly in greenhouse crops, taking the most recent fully expanded leaves and petioles [2,19,28,29,39,40,53,55,56,60]. It is well known that N is a mobile element inside the plant, moving from old to new growth.…”

“…Later, the sample is defrosted, and the ether and chlorophyll solution (green colored fluid) is separated from the sap by a funnel. This methodology was followed by [27,30,[56][57][58]. Some authors also froze and defrosted tissues before pressing, but they did not mention the use of ether in their methods [28,53].…”

“…On the other hand, there are several non-portable methods for analyzing the sap extract (Table 1). While in [26,27,34], atomic absorption spectrophotometry and [30] used high-performance liquid chromatography were used, others [56] used the Kjeldahl method for inorganic forms of N and sulfuric digestion and distillation for the rest of the nutrients. A plasma spectrometer has also been used to analyze sap in citrus [43], while in [2,33], a continuous segmented flow analyzer was used to measure sap levels from tomato and sweet pepper, respectively.…”

Diversidade microbiana envolvida na ciclagem do nitrogênio em solos de cultivo de cana-de-açúcar no estado de São Paulo

“…Diversos autores têm relatado os efeitos positivos da colheita da cana crua sobre a fertilidade e a estrutura do solo, como aumentos nos níveis de carbono e na atividade biológica (RESENDE et al, 2006; Especificamente em relação ao elemento N, sabe-se que a fertilização nitrogenada na agricultura é caracterizada pela possibilidade de grandes perdas de N aplicado. A pesquisa na área de fertilidade do solo busca formas de minimizar essas perdas, evitando problemas ambientais e prejuízos aos produtores (JORIS et al, 2014). Os baixos valores de eficiência dos fertilizantes nitrogenados usados em canaviais estão associados, entre outros fatores, principalmente com efeitos residuais do fertilizante, bem como sua alta imobilização pelos componentes da fração viva do solo (COURTAILLAC et al, 1998).…”