Ciência Brasileira: Múltiplos olhares - Agroecologia, Agronomia, Ciências do Campo e Medicina Veterinária (978-85-5722-568-8) - Altura De Plantas, Número De Folhas E Perfilhos Do Capim-Tanzânia Fertilizado Com Doses De Silicato De Sódio Em Condições De Toxidez Por Alumínio

Because of the lack of agronomic information regarding cultivation of the pink pepper (Schinus terebinthifolius), this study aimed to verify the effect of gypsum and phosphorus on the initial growth and how they affect soil fertility. The treatments consisted of four levels of agricultural gypsum (0; 750; 1,500, and 2,250 mg kg-1) and P2O5 (0; 41.7; 83.4, and 125.1 mg kg-1), with a 4 × 4 factorial arrangement, in a completely randomized design with four replications. Morphological variables and nutritional content taken at 165 days after transplant were shown to be adequate to assess the initial growth and to show their nutritional requirements, indicating that plants are responsive to phosphorus. The association of higher gypsum and P2O5 levels promoted higher plant vigor and their application to the soil increased the availability of calcium, phosphorus, and base saturation.

The aim in developing this work was to summarize information about phosphorus (P) limitation and dynamic in tropical soils for forage grasses production. The major idea is direct information about limited factors affecting P availability, dynamic of P fractionation, P pools, P forms, P use efficiency, and the 4R's Nutrient Stewardship' for P-fertilizer in forage grasses. Organizing these sub-headings in a chapter can result in interesting of how P behaves under tropical soils, in order to take decision to manage P-fertilizer to accomplish forage grasses production with social, economic, and environmental benefits. As the most limiting nutrient in tropical soils, P-fertilizer in forage grasses can be more effective if the best management practices are followed. In order to avoid excess P-fertilizer application in soil or P-fertilizer response with low efficiency, it is important to understand the P dynamic and the factors associated with P adsorption in soil. Even with low amount of P requested to forages species, the P available in soil is quite low, and this knowledge is primordial to direct P-fertilizer. Tropical soils are quite limited in P content, due to the natural formation with parental material poor in P content and highly weathering condition. Thus, in order to improve phosphorus use efficiency, the 4R's must be followed to improve P use efficiency (PUE). It is not easy to improve PUE in highly weathering soil with high buffering capacity; however, all the combination of best management practices for P-fertilizer application can result in better use efficiency. Based on the scarcity of natural P-sources in the whole world, the use of alternative P-sources should be incentivized, and more researches about this issue are need for better understanding.

There is a concern about the growing population and limitation in natural resources which are taking the population to direct its agricultural systems into a more productive and efficient activity, looking to avoid a negative impact on the surrounding environment. The industry energy expended to produce nitrogen (N)-fertilizer is considered an indirect consumption of energy in agriculture, which is higher with an increasing forage yield. Nitrogen is the key nutrient associated with high-yielding production in forage grass and grain crops. The aim of this chapter is to introduce the best management practices (BMPs) for N-fertilizer application in forage grasses to improve N-use efficiency, since the most economical way to feed livestock is forage plants where its potential biomass production is not well explored. The BMPs basically follow three management practices: (1) soil nutrient availability and forage requirement, (2) fertilizer application, and (3) decrease in nutrient losses from soil. In order to take a decision on applying N-fertilizer to accomplish forage grasses production with social, economic, and environmental benefits, the N-fertilizer use in forage grasses is going to follow the ?Right rate, Right source, Right place, and Right time (4R) nutrient stewardship.? The application of the 4R?s nutrients stewardship is directly associated with economic, social, and environmental impact. The capacity of the 4R?s implementation worldwide turns into a best guide to improve the striving of better N-use efficiency in forage grass. The 4R?s are interrelated; thus, the recommendation of N-fertilizer rates cannot be prescribed without the combination of the 4R?s where a whole system to be followed should be considered to decide about N-fertilizer in pasture. Consequently, any decision in one of the 4R?s is going to affect the expected N-fertilizer results and dry matter production.

The purpose of this research was to identify the soil organic matter (SOM) fractions changes in a crop rotation system under no-till system (NTS).This research was carried out from October 2010 to February 2014 in a Rhodic Hapludox.The experiment was set up in completely randomized blocks in a factorial design with eight cover crops and three soil depths (0-5, 5-10 and 10-20 cm) with four repetitions.Cover crops: fall-winter corn, intercropping fall-winter corn with Brachiaria ruziziensis, intercropping fall-winter corn with B. brizantha cv.Marandu, intercropping fall-winter corn with Crotalaria spectabilis, B. ruziziensis, B. brizantha cv.Marandu, Pennisetum glaucum L. and set-aside area.The results of SOM granulometric fractionation showed that 6.5% of the total organic carbon (TOC) stocks were in the particulate organic carbon (POC) fraction.The low values of POC observed in this research are associated with the weather condition of experimental site, which shows high temperature and moisture.In relation to the labile carbon (LC), the highest LC stock was observed in 0-5 cm depth, which differed from the 10-20 cm depth.The POC, LC and labile nitrogen (LN) were the SOM fractions that showed to be more sensitive to detect the changes promoted by the cover crops and soil depths in NTS, as well as the carbon management index (CMI).The intercropping fall-winter corn with B. brizantha cv.Marandu and B. ruziziensis were efficient in increasing the CMI in deeper depth (10-20 cm).

The purpose of this research was to assess the crop rotation affects on agronomic traits of soybean in optimal (OCS) and dry cropping seasons (DCS).This research was carried out in 2010/2011 (OCS) and 2011/2012 (DCS) in a Rhodic Hapludox soil.The experimental design was set up in a randomized complete block and the treatments were arranged in a factorial 9 x 2, consisting of 9 crop rotations systems and two cropping seasons, with four replications.The soybean (Glycine max cv.BMX-Potência RR) was sowed on October 20 th 2010 and October 10 th 2011 (spring-summer season) 20 days after the fall-winter cover crops desiccation.It was assessed in the R8 reproductive stage (Full maturation) the plant height, the height of the first pod insertion, number of pod per plants, number of branches per plant, number of seed per pod, 1000-grain weight and grain yield.It was observed that in drought stress (DCS), the number of branches decreased, this reduction was 36% in relation to OCS.For the traits as plant height, first pod height, 1000-grain weight and yield, it was showed small values in DCS in contrast to OCS.It is feasible to introduce these cover crops in fall-winter season to make part of a crop rotation system.The number of pod per plant showed higher values under the crop rotation of corn/rapeseed/soybean, which showed highly associated with the soybean grain yield.This research brought options for cover crops system to be viable in no-till system with soybean in spring-summer season.

The purpose of this study was to assess the changes in soil chemical properties affected by the cover crops cultivated in crop rotation in short-term of no-till implementation under Rhodic Hapludox soil. This research was carried out from October 2010 to February 2014. The experiment was set up in completely randomized blocks in a factorial design with eight treatments (cover crops) and three soil depths (0-5, 5-10 and 10-20 cm) with four repetitions. The cover crops were: fall-winter maize (T1), intercropping fall-winter maize with B. ruziziensis (T2), intercropping fall-winter maize with B. brizantha cv. Marandu (T3), intercropping fall-winter maize with Crotalaria spectabilis (T4), B. ruziziensis (T5), B. brizantha cv. Marandu (T6), Pennisetum glaucum L. (T7) and fallow (T8). The T6 and T7 affected exchangeable Mg +2 , it was observed higher exchangeable Mg +2 in T6 (2.39 cmolc dm -3 ) and T7 (2.43 cmolc dm -3 ) in comparison to T1. The phosphorus content showed interactive effect between cover crops and soil depth. In the comparison among the depths, the P contents were higher in 5-10 cm, which showed improvement of 24.6% and 25.2% in comparison to 0-5 and 10-20 cm layers, respectively. The cover crops evaluated in this research affected the exchangeable Mg +2 and K + , as well as Mg +2 and K + saturation. The P content changed in response of cover crops, which was important to observe that this nutrient may increase the content with adoption of cover crops in no-till system. The species used in this research might be recommended to integrate a crop rotation system with the possibility of increasing P availability in topsoil depth in no-till system.

Due to lack of agronomic studies with native species and the importance of an adequate supply of nutrients to plants, this study aimed to evaluate the effect of N and P on the concentration and nutrient content as well as the nutritional efficiency of barbatimao (Stryphnodendron polyphyllum) seedlings in Oxisol. The study was conducted in 8 dm(3) pots and kept in a greenhouse. Were studied four doses of N (0, 20.82, 41.64 and 62.46 mg kg(-1) N) and four doses of P (0, 41.72, 83.44 and 125.16 mg kg(-1) P2O5) in 4x4 factorial in randomized complete block design with four replications. After 210 days after sowing was evaluated dry mass of shoots and roots and nutrient concentration in the plant, through these data were calculated the efficiency of absorption and utilization of nutrients. There was significant interaction between doses of N and P to the concentration of P, K, Ca, Cu, Mn and Zn in shoots and N, P, K, Ca, Mg and Fe in the root. In seedling nutrients N and Fe were influenced only by the isolated effect of N levels, and Mg content by isolated effect of P levels. The content of all nutrients in the shoot and root was significantly influenced by the interaction between doses of N and P. The maximum doses provided greater nutrient contents in shoots, except for N and K. The micronutrients content in the shoot increased as a function of both N and P and reduced the root, except Fe. The barbatimao seedlings were more efficient at absorbing N and Zn and using P and Mg. Comparing the content, N and Ca were the nutrients that most accumulated on the plant tissues, however, those who had lower (P and Mg) were the nutrients more efficiently used.

The purpose of this research was to assess the effects of replacement of native “Cerrado” vegetation (NV) into croplands on soil chemical, physical and microbial properties. This research was carried out on a farm under Rhodic Hapludox soil with different types of agricultural managements systems, and it was used a NV to compare the systems. The experimental design was set up in completely randomized with five treatments and five repetitions. The treatments adopted were several agricultural management systems as follow; NV; CS_Crop system; LS_Livestock system; ICLS-4_Integrated crop-livestock system with four years of implementation; ICLS-8_Integrated crop-livestock system with eight years of implementation. It was assessed some chemical, physical, and microbial parameters in the soil, as soil pH, P content, exchangeable cations, cation exchange capacity, base saturation, cations saturation, soil organic carbon (SOC), soil bulk density (SBD), aggregate stability, microbial biomass carbon (MBC), basal breathing, and microbial quotient. The replacement of NV to ICLS decreased SOC, MBC, soil aggregate stability and increase of SBD. The ICLS improved “Cerrado” soil fertility over time adoption. This integrated system increased the quantity of exchangeable K + and P content in “Cerrado” soil. The ICLS-8 showed soil environment nearby the NV. Even the difficulty in obtaining the same physical and microbial condition of NV, the results of this research point out quite important observations, because just no-till system is not enough to obtain improvement of soil quality and the ICLS can return the soil properties close to native “Cerrado” vegetation.

Devido à carência de estudos agronômicos com espécies nativas e da importância do adequado fornecimento de nutrientes às plantas, objetivou-se neste trabalho avaliar o efeito de doses de N e P sobre o teor e conteúdo de nutrientes, bem como na eficiência nutricional de mudas de barbatimão (Stryphnodendron polyphyllum), em Latossolo Vermelho distroférrico. O trabalho foi desenvolvido em vasos de 8 dm3, mantidos em casa de vegetação. Foram estudadas quatro doses de N (0; 20,82; 41,64 e 62,46 mg kg-1 de N) e quatro doses de P (0; 41,72; 83,44 e 125,16 mg kg-1 de P2O5), em esquema fatorial 4 x 4, no delineamento experimental de blocos casualizados, com quatro repetições. Decorridos 210 dias após a semeadura avaliou-se massa seca da parte aérea e radicular e teor de macro e micronutrientes na planta; por meio desses dados foram calculados os índices de eficiência de absorção e utilização de nutrientes. Houve interação significativa entre as doses de N e P para os teores de P, K, Ca, Cu, Mn e Zn na parte aérea e N, P, K, Ca, Mg e Fe na raiz. Na parte aérea das mudas, os nutrientes N e Fe foram influenciados somente pelo efeito isolado das doses de N, e o teor de Mg pelo efeito isolado das doses de P. O conteúdo de todos os nutrientes, na parte aérea e na raiz, foi influenciado significativamente pela interação entre as doses de N e P. As máximas doses proporcionaram maior conteúdo de macronutrientes na parte aérea, exceto N e K. O conteúdo de micronutrientes na parte aérea aumentou em função das doses de N e P e reduziu na raiz, exceto Fe. As mudas de barbatimão mostraram-se mais eficientes em absorver N e Zn e utilizar P e Mg. Comparados ao conteúdo, o N e o Ca foram os nutrientes mais acumulados nos tecidos da planta, contudo, os que apresentaram menor valor (P e Mg) foram os nutrientes mais eficientemente utilizados.

The objective of this work was to determine the effect of off-season corn intercropped with Urochloa brizantha 'Marandu' and of nitrogen sources on the granulometric fractions of soil organic matter under a notillage system. The treatments were arranged in a 2x4 factorial arrangement - two types of corn cultivation (with or without pasture) and four nitrogen sources (without nitrogen, urea, ammonium sulfate+urea, and ammonium sulfate) -, in randomized complete blocks with four replicates. The experiment was carried out from 2005 to 2013. Soil sampling was performed in 2013, after corn harvest in fall/winter, at four depths: 0-5, 5-10, 10-20, and 20-40 cm. Total (TOC), labile (LC), particulate (POC), and mineral-associated organic carbon (MOC) contents were determined. The intercropping of corn with U. brizantha 'Marandu' results in a higher concentration of TOC, LC, and POC than single corn cultivated in fall/winter. Ammonium sulfate+urea increases TOC contents at the 0-5-cm depth, but decreases them at the 20-40-cm depth, besides increasing the MOC contents at all depths. The highest total, labile, and particulate organic carbon contents are observed at the 0-5 and 5-10-cm depths.

Resumo: O objetivo deste trabalho foi determinar o efeito do consórcio de milho safrinha com Urochloa brizantha 'Marandu' e de fontes de nitrogênio nas frações granulométricas da matéria orgânica do solo em sistema plantio direto. Os tratamentos foram dispostos em arranjo fatorial 2x4 - dois tipos de cultivo de milho (com ou sem pasto) e quatro fontes de nitrogênio (sem nitrogênio, ureia, sulfato de amônio+ureia e sulfato de amônio) -, em blocos ao acaso, com quatro repetições. O experimento foi conduzido de 2005 a 2013. As coletas do solo foram realizadas em 2013, após a colheita do milho no outono/inverno, em quatro profundidades: 0-5, 5-10, 10-20 e 20-40 cm. Foram determinados os teores de carbono orgânico total (COT), lábil (CL), particulado (COP) e mineral (COM). O consórcio de milho com U. brizantha 'Marandu' resulta em maior teor de COT, CL e COP do que o cultivo de milho solteiro no outono/inverno. O sulfato de amônio+ureia aumenta os teores de COT na camada de 0-5 cm, mas os diminui na de 20-40 cm, além de incrementar os teores de COM em todas as profundidades. Os maiores teores de carbono orgânico total, lábil e particulado são verificados nas profundidades de 0-5 e 5-10 cm.

The purpose of this research was to evaluate soybean agronomic traits performance under row spacing associated with NPK fertilizer. The experimental design was set up in a randomized complete block and the treatments were arranged with factorial concept, consisting of four NPK (02-20-18%) fertilizer rates (0; 200; 400 and 600 kg ha-1) and five row spacing (0.35; 0.45; 0.50; 0.60 and 0.70 m), with three replications. The measurements were performed in two consecutive cropping seasons. The following variables were determined: time of canopy closure; plant height; the height of the first pod insertion; number of pods per plant; number of branches per plant; number of grains per pod; 1000-grain weight; and grain yield. The narrow row spacing (below than 0.40 m) may be a profitable alternative to reduce intraspecific plant competition resulting in improvement of soybean agronomic performance, resulting faster canopy closure and relative equidistance among soybean plants. Narrow rows promoted increase in soybean grain yield. The row spacing of 0.35 m associated with 600 kg ha-1 of NPK fertilizer was the profitable combination to achieve the highest soybean grain yield. The wide row spacing demand more fertilizer to remain the same performance than in 0.35 m spacing row. Key words: Glycine max L., soil fertility, cropping season, soil science.

The use of compositional nutrient diagnosis (CND) to assess the nutritional status of cotton crop is quite important to improve knowledge on plant nutritional requirement and assist the fertilizer recommendation. The aim of this chapter is to introduce the possibility of using CND for cotton crop. This method has scarcely been used to assess the nutritional status of cotton plant although a few results have indicated that it can be promising. In fact, CND methodology seems to be better in the nutritional diagnosis than traditional methods such as sufficient range (SR) and critical value approach (CVA). Its efficiency has increased with the possibility of applying multivariate analysis, principal component analysis (PCA), canonical correlation, and so on. The application of PCA possibility to note some interactions among the nutrients is important for understanding the dynamics of nutrients in plants.

The aim of this research was to assess the effect of lime management under no-till system implementation to evaluate the millet cover crop and soybean performance. This experiment was carried out during the years 2012 and 2013 in the municipality of Ponta Pora, state of Mato Grosso do Sul, Brazil. The experimental design in blocks with four replicates and three treatments (Treat-1; Lime surface application without incorporation; Treat-2; Lime surface application and incorporated with intermediate disk harrow followed by leveling disk harrow; Treat-3; Lime surface application and incorporated with chisel plow, followed by intermediate disk harrow and leveling disk harrow), the amount of lime was 2.7 tonnes ha-1. The crops evaluated were millet ('Pennisetum glaucum' cv. BRS-1501) and soybean ('Glycine max' cv. BMX-Potencia RR) in crop rotation. The millet was planted as cover crop to produce above-ground dry mass. The soybean was sowed under millet dry mass in no-till system. After 12 months from planting, the lime management promoted chemical and physical changes in soil properties through the profile. The Treat-2 and 3 resulted in better lime incorporation in the layer 10-20 cm and 20-30 cm. The highest dry mass of millet was obtained in Treat-2 (6,460 kg ha-1) and Treat-3 (6,690 kg ha-1). The highest soybean productivity (3,330 kg ha-1) was reached in Treat-3. The absence of lime incorporation into the soil caused decrease in millet and soybean production. Even if the soil chemical is adequate for a good performance for crops, the SPR may limit the root development. The Treat-2 and 3 reduced the SPR and increased the vegetable production of soybean and millet.

A ambiencia de precisao na agricultura e de fundamental importância para manter a sustentabilidade e a lucratividade da producao. O objetivo deste estudo e mostrar algumas das ferramentas utilizadas na manipulacao da ambiencia da agricultura. O trabalho foi desenvolvido por meio de pesquisa bibliografica. Os resultados mostram que a ambiencia sustentavel na agricultura permite o uso de tecnologias na previsao da produtividade das culturas, fazendo o levantamento de campo, estimativa da area cultivada, bem como atuar de forma sustentavel. As ferramentas do geoprocessamento podem ser utilizadas em diferentes areas da agricultura, tais como: para dimensionar o uso de insumos na fertilizacao e correcao dos solos; na mecanizacao para identificar os tipos de maquinas podendo ser usadas nas diferentes areas agricultaveis; no mapeamento da disponibilidade de agua no solo; identificacao do clima e temperatura da regiao; mapeamento de pragas e ervas daninhas que podem atacar a cultura e no dimensionamento da produtividade entre outras aplicacoes decorrentes da diversidade agricola. O uso de tecnologias de precisao aumenta a produtividade e melhora o controle da area cultivada mediante o conhecimento da variacao do rendimento de producao de local para local. Ao dimensionar a ambiencia, o gestor rural tem uma nova visao da producao agricola, promovendo maior eficiencia na tomada de decisao e no manejo da producao

Due to the high temperature and moisture in the region of Brazilian “Cerrado”, the greatest challenge in no-till system is the maintenance of above-ground dry matter. The aim of this research was to assess the above-ground dry matter production from cover crops and its effects on soybean and corn yield in Brazilian “Cerrado”. The experiment was carried out from 2012 to 2014 growing seasons. The experimental design was randomized blocks with four repetitions. The treatments (T) adopted were formed by different cover crops [fall-winter corn crop (T1); intercropping fall-winter corn with Brachiaria ruziziensis (T2); intercropping fall-winter corn with Brachiaria brizantha cv. Marandu (T3); intercropping fall-winter corn with Crotalaria spectabilis (T4); B. ruziziensis (T5); B. brizantha cv. Marandu (T6); Penisetum glaucum L. (T7) and reference area (T8)]. The above-ground dry matter productions were influenced by the treatments assessed through two growing seasons (2012/2013 and 2013/2014). There was interaction between the cover crops and growing seasons for above-ground dry matter of the cover crops. In relation to fall-winter corn yield, the cover crops and growing seasons showed significant effect on corn yield. The cover crops effect on soybean yield. The cultivation of intercropping fall-winter corn crop with B. brizantha cv. Marandu or this forage grass single showed higher production of aboveground dry matter, these values reached quantities over than 6 Mg ha -1 . The soybean crop yield decreased because of the aboveground dry matter production of the cover crop of B. brizantha cv. Marandu and the intercropping fall-winter corn with B. brizantha cv. Marandu.

The development of nutrients optimum range (NOR) is quite important for the ratoon sugarcane (Saccharum spp.) to help decision making of fertilizers management. The purpose of this study was to establish NOR from statistical models of relationship between leaf nutrient content (LNC) and DRIS indices. In this study, the nutritional status of the first ratoon sugarcane crop was assessed based on NOR. The study was performed using data from the first ratoon sugarcane obtained from commercial fields, in the southern region of Goi s State, in Brazil. Yield data from plots (average acreage 20 ha) and LNC of macro- and micronutrients in 2012/2013 cropping season were stored in a database. The procedure to define the reference population (high-yielding subpopulation) consisted of plots with above-average yield + 2/3 standard deviation (over 200.94 tonnes ha-1). The average and coefficient of variation for each dual ratio between nutrient concentration (N/P, N/K, N/Ca, etc.) were measured in the high-yielding subpopulation, which was considered the DRIS norms. Based on DRIS norms at the first ratoon sugarcane, it was possible to develop NOR and assess the nutritional status of sugarcane crop. The evaluation of the nutritional status using the NOR indicated that K (87.36%), P (81.82%), Zn (67.27%) and Cu (76.36%) were the nutrients that showed the most deficiency among the plots assessed. On the other hand, N (69.09%), Ca (60%) and S (70.91%) were the most excess nutrients.

With the expansion of the sugarcane cropping area in Brazil, it is necessary to study the changes that this crop may affect to the soil organic matter storage (SOM). The aim of this research was to quantify the carbon management index (CMI), total organic carbon stocks (TOC), labile carbon (LC) and carbon amount in the oxidized fractions of SOM in cropping soil cultivated by sugarcane crop. The experiment was carried out in the sugarcane crop farm located in a dystroferric Red Latosol. The experimental design was completely randomized with four replications. The treatments were comprised of: reference area (RA), area cultivated with sugarcane crop for one year (AC1yr), two years (AC2yr), three years (AC3yr), and four years (AC4yr). The soil samples were collected at two depths (0-10 and 10-30 cm). The highest TOC stock was observed in the treatment AC4yr (15.32 Mg ha-1), which differed from the RA (11.01 Mg ha-1) at 0-10 cm depth. No significant difference was observed in LC at 0-10 cm depth. The treatment AC3yr and AC4yr showed the highest value of LC stocks differing from RA and AC1yr (10-30 cm). There was significant increasing in total organic carbon stocks and labile carbon, indicating the capacity of sugarcane crop on mitigation of greenhouse gases. It also promoted a balanced distribution in the TOC stocks in the fraction of oxidized OM (F1+F2 and F3+F4).