Precision production environments for sugarcane fields

Sugarcane (saccharum spp.) in Brazil is managed on the basis of “production environments”. These “production environments” are used for many purposes, such as variety allocation, application of fertilizers and definition of the planting and harvesting periods. A quality classification is essential to ensure high economic returns. However, the classification is carried out by few and, most of the time, non-representative soil samples, showing unreal local conditions of soil spatial variability and resulting in classifications that are imprecise. One of the important tools in the precision agriculture technological package is the apparent electrical conductivity (ECa) sensors that can quickly map soil spatial variability with high-resolution and at low-cost. The aim of the present work was to show that soil ECa maps are able to assist classification of the "production environments" in sugarcane fields and rapidly and accurately reflect the yield potential. Two sugarcane fields (35 and 100 ha) were mapped with an electromagnetic induction sensor to measure soil ECa and were sampled by a dense sampling grid. The results showed that the ECa technique was able to reflect mainly the spatial variability of the clay content, evidencing regions with different yield potentials, guiding soil sampling to soil classification that is both more secure and more accurate. Furthermore, ECa allowed for more precise classification, where new “production environments”, different from those previously defined by the traditional sampling methods, were revealed. Thus, sugarcane growers will be able to allocate suitable varieties and fertilize their agricultural fields in a coherent way with higher quality, guaranteeing greater sustainability and economic return on their production

Evaluación de la densidad de plantas, componentes fenológicos de producción y rendimiento de granos en diferentes materiales genéticos de maíz

ABSTRACT The aim of this study was to verify the influence of planting distance and the population of plants, phenological components, and productivity in different maize genetic material. The experiment was conducted during the 2003/04 agricultural year in the city of Jaú/SP, located at latitude 22° 17'S, longitude 48° 34' W and altitude 680 m. Average Were studied, planting distances of 0.45 m and 0.90 m, three densities 50, 75 and 100 000 plants ha-1, and four genetic materials: simple hybrid DKB 333C, triple hybrid DKB 466, AG 2060 and double hybrid the variety AL 2x3x4 factorial scheme Bandeirantes in with 4 replications in randomized blocks. The reduction in the planting row spacing and increasing plant population significantly influenced the percentage of lodged plants and broken corn. Line spacing of 0.45 m, population of 75,000 plants ha-1 and single hybrid material showed the highest productivity of grains with an average of 9077 kg ha-1. Significant interactions were observed line spacing factors versus population of plants and plant population versus materials for grain productivity factor. Phonological components of production: spike length, shank diameter and the diameter of the cobs were influenced by increased plant population ha-1. The experiment was conducted during the agricultural year of2003/04 in the city of Jaú/SP, located at latitude 22° 17'S and longitude 48° 34' Wand an average altitude of 680 m. Were tested, two spacing 0.45 m and 0.90 m, three densities 50, 75 and 100 thousand plants ha-1, and four genetic materials simple hybrid DKB 333C, triple hybrid DKB 466, double hybrid and variety AG 2060 in AL Bandeirantes® factorial design 2x3x4 with 4 replications in randomized blocks.RESUMEN El objetivo del estudio fue verificar la influencia de la distancia de plantación y de la población de plantas, en los compo nentes fenológicos y en la productividad de diferentes materiales genéticos de maíz. El experimento fue conducido en el municipio de Jaú/SP, localizado en la latitud 22° 17' S, longitud 48° 34' W y altitud media de 680 msnm. Fueron estudiadas dos distancias de plantación: 0,45 m y 0,90 m, tres densidades poblacionales 50, 75 y 100 mil plantas ha-1, y cuatro materia les genéticos: híbrido simple DKB 333C, híbrido triple DKB 466, híbrido doble AG 2060 y la variedad AL Bandeirantes® en esquema factorial 2x3x4 con cuatro repeticiones en bloques al azar. La reducción en la distancia entre líneas de plantío y el aumento de la población de plantas influenciaron significativamente en el porcentaje de plantas acamadas y quebradas del maíz. Espacio entre líneas de 0,45 m, población de 75.000 plantas ha-1 y material híbrido simple presentaron la mayor productividad de granos con promedio de 9.077 kg ha-1. Se observaron interacciones significativas de los factores distancia entre líneas versus población de plantas, y población de plantas versus materiales para el factor productividad de granos. Los componentes fenológicos de producción: largo de la mazorca, diámetro de la mazorca y diámetro de la tusa (marlo) fueron influenciados por el aumento de población de plantas ha-1

Nitrogen source contribution in sugarcane-inoculated plants with diazotrophic bacterias under urea-N fertigation management

Although Brazilian sugarcane crops use lower nitrogen rates when compared to other producing countries, the biological nitrogen fixation (BFN) could be performed aiming to reduce costs, since almost all nitrogen fertilization used in Brazil is imported. BFN can occur in sugarcane; however, its role in non-leguminous plants is controversial. Therefore, this study aimed to assess the nitrogen source contribution (using N isotope N-15 technique) along a growing period in sugarcane plants under different management (diazotrophic bacteria inoculation and N fertigation rates). The natural abundance of nitrogen isotope (N-15) abundance in +1 leaves of fourth ratoon cultivar SP 80-3280 was used to indicate the comparative importance of N sources, including BFN for sugarcane nutrition. The treatments were irrigated with two levels of nitrogen fertilizer 50 and 100kgha(-1) (urea source), including a control without fertilizer, with (I) and without (NI) inoculation of nitrogen-fixing bacterias. The bacteria cocktail used consisted of five strains: Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae, H. rubrisubalbicans, Burkholderia tropica and Azospirillum amazonense. Although the nitrogen content in +1 leaves, the above ground dry matter, cane yield and stalk sugar content expanded by increasing nitrogen fertilizer rates, no significant interactions between nitrogen-fixing bacteria inoculation and nitrogen fertilizer rates were observed. In the treatment without N fertilizer application, no differences in N-15 parts per thousand (per thousand) values between sugarcane-inoculated and sugarcane-non-inoculated sugarcane leaves was found. The temporal variation of N-15 parts per thousand in sugarcane +1 leaves indicated that nitrogen content and N-15 parts per thousand values decreased during the phenological development stages and that the main sources of nitrogen for sugarcane were from synthetic fertilizer and mineralization of nitrogen from soil organic matter213462470FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2008/56.147-

Precision production environments for sugarcane fields

Sugarcane (saccharum spp.) in Brazil is managed on the basis of "production environments". These "production environments" are used for many purposes, such as variety allocation, application of fertilizers and definition of the planting and harvesting periods. A quality classification is essential to ensure high economic returns. However, the classification is carried out by few and, most of the time, non-representative soil samples, showing unreal local conditions of soil spatial variability and resulting in classifications that are imprecise. One of the important tools in the precision agriculture technological package is the apparent electrical conductivity (ECa) sensors that can quickly map soil spatial variability with high-resolution and at low-cost. The aim of the present work was to show that soil ECa maps are able to assist classification of the "production environments" in sugarcane fields and rapidly and accurately reflect the yield potential. Two sugarcane fields (35 and 100 ha) were mapped with an electromagnetic induction sensor to measure soil ECa and were sampled by a dense sampling grid. The results showed that the ECa technique was able to reflect mainly the spatial variability of the clay content, evidencing regions with different yield potentials, guiding soil sampling to soil classification that is both more secure and more accurate. Furthermore, ECa allowed for more precise classification, where new "production environments", different from those previously defined by the traditional sampling methods, were revealed. Thus, sugarcane growers will be able to allocate suitable varieties and fertilize their agricultural fields in a coherent way with higher quality, guaranteeing greater sustainability and economic return on their production7611017FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2013/50942-2; 2014/14965-

Precision production environments for sugarcane fields

ABSTRACT: Sugarcane (saccharum spp.) in Brazil is managed on the basis of “production environments”. These “production environments” are used for many purposes, such as variety allocation, application of fertilizers and definition of the planting and harvesting periods. A quality classification is essential to ensure high economic returns. However, the classification is carried out by few and, most of the time, non-representative soil samples, showing unreal local conditions of soil spatial variability and resulting in classifications that are imprecise. One of the important tools in the precision agriculture technological package is the apparent electrical conductivity (ECa) sensors that can quickly map soil spatial variability with high-resolution and at low-cost. The aim of the present work was to show that soil ECa maps are able to assist classification of the “production environments” in sugarcane fields and rapidly and accurately reflect the yield potential. Two sugarcane fields (35 and 100 ha) were mapped with an electromagnetic induction sensor to measure soil ECa and were sampled by a dense sampling grid. The results showed that the ECa technique was able to reflect mainly the spatial variability of the clay content, evidencing regions with different yield potentials, guiding soil sampling to soil classification that is both more secure and more accurate. Furthermore, ECa allowed for more precise classification, where new “production environments”, different from those previously defined by the traditional sampling methods, were revealed. Thus, sugarcane growers will be able to allocate suitable varieties and fertilize their agricultural fields in a coherent way with higher quality, guaranteeing greater sustainability and economic return on their production

Multilocation straw removal effects on sugarcane yield in south-central Brazil

Sugarcane straw is a crop residue that has a dual purpose and can be maintained on the fields or used to produce bioenergy. The straw retention in the field provides multiple ecosystem services, and the complex interactions between straw and yield responses are hard to predict by local studies. The aim of this study was to investigate the straw removal effects on sugarcane yield in south-central Brazil. To achieve the objective, a set of 21 field studies was conducted in contrasting edaphoclimatic conditions. In addition, data of seven studies from the literature were included to build a more robust dataset. Since straw removal treatments were not homogeneous in all experiments, they were grouped as follows: NR, no removal (baseline treatment); LR, low removal; MR, moderate removal; and TR, total removal. To facilitate the data analysis, the experiments were gathered in four macroregions: southern Goias, western Sao Paulo, central-eastern Sao Paulo, and northeastern Sao Paulo. The site location was the most effective individual factor to explain the straw removal effects on sugarcane yields. Compared with NR treatment, the average yield losses induced by LR, MR, and TR were 2, 10, and 13 Mg ha(-1) in southern Goias and 2, 4, and 6 Mg ha(-1) in western Sao Paulo states, respectively. In other regions, no clear pattern was observed, and only site-specific effects were observed. Straw removal affected sugarcane yields in all soil types, but higher responses were observed under best conditions for sugarcane growth (i.e., clayey soils in southern Goias). Our findings indicated harvesting season has a relevant role on determining yield responses to straw removal and younger ratoons are more responsive to straw removal. Conclusions from this study suggest straw removal recommendations cannot be designed based on isolated factors but require holistic and integrated knowledge to ensure that the straw amount left on field is enough to sustain multiple soil ecosystem services and crop yields12481382