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All publications of “Rafael Otto”

10 results

Nutrient Uptake by High-Yielding Cotton Crop in Brazil

José Luís Vilela Vieira, Kaue Tonelli Nardi, Gabriel Rodrigues Anastácio Silva, Lílian Angélica Moreira, Eduardo Zavaschi, Thiago Augusto Moura, [...]


ABSTRACT: Determining nutrient uptake and accumulation rates by cotton crops is important to define management strategies, especially for transgenic varieties, which are cultivated using high-technology approaches that require substantial investment to maximize yield. Currently in Brazil, the states of Bahia and Mato Grosso are responsible for 84.4 % of the total cotton growing area. In the present study, two trials were conducted in 2013, one that involved planting FM 940 GLT, FM 980 GLT, and FM 913 GLT varieties in […]

Incubation methods for assessing mineralizable nitrogen in soils under sugarcane

Eduardo Mariano, Paulo Cesar Ocheuze Trivelin, José Marcos Leite, Michele Xavier Vieira Megda, Rafael Otto, Henrique Coutinho Junqueira Franco


Considering nitrogen mineralization (N) of soil organic matter is a key aspect for the efficient management of N fertilizers in agricultural systems. Long-term aerobic incubation is the standard technique for calibrating the chemical extraction methods used to estimate the potentially mineralizable N in soil. However, the technique is laborious, expensive and time-consuming. In this context, the aims of this study were to determine the amount of soil mineralizable N in the 0-60 cm layer and to evaluate the use of […]

Ammonia losses estimated by an open collector from urea applied to sugarcane straw

Eduardo Mariano, Paulo Cesar Ocheuze Trivelin, Michele Xavier Vieira, José Marcos Leite, Rafael Otto, Henrique Coutinho Junqueira Franco


The quantification of ammonia (NH3) losses from sugarcane straw fertilized with urea can be performed with collectors that recover the NH3 in acid-treated absorbers. Thus, the use of an open NH3 collector with a polytetrafluoroethylene (PTFE)-wrapped absorber is an interesting option since its cost is low, handling easy and microclimatic conditions irrelevant. The aim of this study was to evaluate the efficiency of an open collector for quantifying NH3-N volatilized from urea applied over the sugarcane straw. The experiment was […]

Potassium fertilizer management for sugar cane

Rafael Otto, Godofredo Cesar Vitti, Pedro Henrique de Cerqueira Luz


Brazil is the largest sugar cane producer in the world and, due to the increasing interest in renewable energy sources, the cultivated area is expanding. Sugar cane is usually planted in soil with low nutrient levels, which can limit the yield. In sugar cane, potassium is basically applied in the furrow, which can decrease the K use efficiency due to leaching or salinizaton to plant roots. The goal of this study was to evaluate stalk yield and technological properties of […]

Ammonium chloride as nitrogen source in sugarcane harvested without burning

Michele Xavier Vieira, Paulo Cesar Ocheuze Trivelin, Henrique Coutinho Junqueira Franco, Rafael Otto, Carlos Eduardo Faroni


The great difficulty of incorporation of N fertilizers into the “green sugarcane” system causes concern and since urea is the most commonly used source, there is the risk of loosing NH3 through volatilization. For this reason, a field experiment was undertaken (in a Hapludox Typic) with the objective of evaluating the agronomic efficiency of ammonium chloride on stubble of the second ratoon (SP89 1115), as well as its residual effect on the subsequent cycle (third ratoon). The experimental design was randomized […]

Nutritional status of sugar cane (planted cane) in 15N experiments

Carlos Eduardo Faroni, Paulo Cesar Ocheuze Trivelin, Henrique Coutinho Junqueira Franco, André Cesar Vitti, Rafael Otto, Heitor Cantarella


Studies with stable isotopes are becoming more common due to the increased safety of operation and quality and reliability of results. However, the use of microplots is required to decrease the costs of such studies. Since microplots are small compared to regular plot areas, the purpose of this study was to investigate whether nutritional data based on microplot samples can adequately represent the whole area, in a comparison of the nutritional status of microplot sugar cane plants at their maximum […]

Utilization of Boron (10B) derived from fertilizer by sugar cane

Henrique Coutinho Junqueira Franco, Paulo Cesar Ocheuze Trivelin, André César Vitti, Rafael Otto, Carlos Eduardo Faroni, João Gabriel Tovajar


The response to B in agricultural systems of sugar cane is still an unexplored issue; B application has however recently been widely publicized and used with a certain degree of frequency. The use of 10B-labeled fertilizers may further contribute to clarify this practice. With the objective of evaluating sugar cane use of B (10B) derived from fertilizer (boric acid), an experiment was conducted under field conditions in the 2005/2006 growing season. The experiment consisted of the installation of microplots (2 […]

Root system distribution of sugar cane as related to nitrogen fertilization, evaluated by two methods: monolith and probes

Rafael Otto, Paulo Cesar Ocheuze Trivelin, Henrique Coutinho Junqueira Franco, Carlos Eduardo Faroni, André Cesar Vitti


Few studies on sugar cane have evaluated the root system of the crop, in spite of its importance. This is mainly due to the difficulty of evaluation and high variability of results. The objective of this study was to develop an evaluation method of the cane root system by means of probes so as to evaluate the mass, distribution and metabolically active roots related to N fertilization at planting. For this purpose, an experiment was conducted in an Arenic Kandiustults […]

Straw mineralization and root growth of sugar cane as related to nitrogen fertilization at planting

André Cesar Vitti, Paulo Cesar Ocheuze Trivelin, Heitor Cantarella, Henrique Coutinho Junqueira Franco, Carlos Eduardo Faroni, Rafael Otto, [...]


The experiment was conducted with the sugar cane variety SP81 3250, in a commercial area of the sugar mill São Martinho (Pradópolis-SP), on a clay-texture Rhodic eutrustox. The experimental had a randomized block design with four replications. Bags containing straw enriched with 15N (1.07 % 15N atoms) equivalent to 9 t ha-1 dry matter were placed on the soil surface between the sugar cane plant rows in all treatments (0, 40, 80 and 120 kg ha-1 of N). After 14 […]

Utilization by sugar cane of nitrogen applied at planting

Henrique Coutinho Junqueira Franco, Paulo Cesar Ocheuze Trivelin, Carlos Eduardo Faroni, André Cesar Vitti, Rafael Otto


The 15N balance of N sources in the soil-plant system is of great value in studies of N transformation in different agroecosystems. In the sugarcane agroecosystem, the cane plant response to N fertilization for Brazilian conditions is not fully understood and the use of N fertilizer labeled with 15N can help clarify this issue. To evaluate the urea-N utilization by sugarcane at plant cane harvest, two experiments were developed with the variety SP81-3250, in commercial sugarcane fields. The experiments were […]