Macronutrient Uptake And Removal By Upland Rice Cultivars With Different Plant Architecture

Modern high-yielding rice cultivars possibly take up and remove greater quantities of macronutrients than traditional and intermediate cultivars. This study was carried out with the aim of evaluating the extraction and removal of macronutrients by upland rice cultivars. These information are of utmost importance for the correct fertilizer management. The treatments consisted of three upland rice cultivars (Caiapó, a traditional type; BRS Primavera, an intermediate type; and Maravilha, a modern type). Macronutrient accumulation by rice cultivars up to the end of tillering (46 DAE) accounted for only 25 % of the total N and P, and between 35-45 % of the total K, Ca, Mg, and S; after that time, accumulation was intensified. In all of the cultivars, the period of greatest nutrient uptake occurred from 45 to 60 DAE for K, Ca, Mg, and S, and after 65 DAE for N. Phosphorus was taken up at greater rates at 70 DAE by the cultivar BRS Primavera and after 90 DAE by the cultivars Caiapó and Maravilha. The cultivars of the traditional (Caiapó) and intermediate (BRS Primavera) groups took up greater amounts of Ca (143 kg ha-1), Mg (46-53 kg ha-1), and S (45-52 kg ha-1), but amounts of N (147-156 kg ha-1) and P (18-19 kg ha-1) were similar to those of the cultivar of the modern group (Maravilha). Caiapó cultivar took up more K (245 kg ha-1) than other cultivars (204-207 kg ha-1). The cultivars Caiapó and Maravilha showed similar grain yield (4,157 and 4,094 kg ha-1); however, this was lower than the grain yield of cultivar BRS Primavera (6,010 kg ha-1). Cultivars with greater yield levels did not necessarily exhibit a greater uptake and removal of nutrients per area, even if they had greater capacity for conversion of the nutrients taken up into the biomass. © 2016, Revista Brasileira de Ciencia do Solo. All rights reserved.4

Efeitos Residuais Da Calagem Superficial Em Solo Tropical Com Plantio Direto

The objective of this work was to evaluate the long-term effects of the surface application of lime on soil fertility and on the mineral nutrition and grain yield of soybean, and of black oat and sorghum in crop succession. The experiment was carried out on a clayey Oxisol, in a randomized complete block design, with four replicates. Treatments consisted of lime the rates of 0, 1,000, 2,000, and 4,000 kg ha-1, applied in October 2002 and November 2004. Soil samples were collected at five soil layers, down to 0.60-m depth. Surface liming was effective in reducing soil acidity and increasing Ca2+ and Mg2+ contents in the subsurface. Moreover, it increased available phosphorus contents and soil organic matter in the long term (48 to 60 months after the last lime application). Surface liming improved plant nutrition, mainly for N, Ca, and Mg, and increased dry matter production and grain yield of the crops, even in years with regular distribution of rainfall. The greatest productivities of soybean, black oat, and sorghum were obtained with the respective estimated lime doses of 4,000, 2,333, and 3,281 kg ha-1, for shoot dry matter, and of 2,550, 3,555, and over 4,000 kg ha-1, for grain yield.5191633164

Influência De Níveis De Potássio No Crescimento Radicular E Na Absorção De Nutrientes Em Cultivares De Arroz De Terras Altas

Potassium (K) is an essential nutrient for upland rice growth, but little information on the effects of K on root growth and nutrient uptake capacity of upland rice is found. Therefore, an experiment was conducted under greenhouse conditions to evaluate the influence of soil K levels on root growth and nutrient uptake of four upland rice cultivars. A completely randomized experimental design, in a 4x4 factorial scheme (4 levels of K: 20, 40, 80, and 160 mg dm-3; 4 cultivars: Caiapó, BRS-Primavera, IAC-202, and Maravilha) was used, with four replications. Based on regression equations, the highest values of root length density would be found with 136 mg dm-3 of K. The root diameter and dry matter, shoot dry matter and shoot K concentration increased linearly with the increasing K rates. The shoot K concentration of the upland rice cultivars did not differ. The increased level of K in the soil reduced the shoot Ca concentration of intermediate and modern cultivars, and the shoot Mg concentration of all cultivars. The potassium fertilization increased the plant growth, but the magnitude of this effect varied according to the cultivar. © 2017, Universidade Federal Rural do Semi-Arid. All Rights Reserved.301324

Silage Production Of Corn Intercropped With Tropical Forages In An Integrated Crop-livestock System With Lambs

The objective of this work was to evaluate the effect of intercropping systems between corn and tropical forages, at different cutting heights, on silage production, light interception, land use efficiency, intercropping competition factors, and pasture production. In the 2010/2011 and 2011/2012 crop seasons, two cultivation modalities were evaluated in the summer/autumn - monocropped corn with residual regrowth of signal grass (Urochloa decumbens) from the soil seed bank and corn intercropped with palisade grass (U. brizantha 'Marandu') -, in a factorial arrangement with two cutting heights for silage production - 0.20 and 0.45 m. After corn silage harvest, the forages were grazed by lambs in a semi-feedlot system, in the winter/spring. Monocropped corn and 0.45-m cutting height both reduced dry matter yield for silage. Corn intercropped with palisade grass improved land use efficiency from 13 to 31% compared with monocropped crop, with land equivalent ratio greater than 1. Palisade grass showed higher light interception than signal grass over the intercrop period with corn and provided greater forage yield for lambs to graze during winter/spring. Corn intercropped with palisade grass, compared with monocropped corn, especially at the cutting height of 0.45 m, is a viable option for improving silage and pasture production, as well as land use efficiency in the integrated crop-livestock system.521546

Yield And Nutritive Value Of The Silage Of Corn Intercropped With Tropical Perennial Grasses

The objective of this work was to compare the yield and nutritive value of the silage of corn intercropped with palisade grass (Urochloa brizantha 'Marandu') or guinea grass (Megathyrsus maximus 'Tanzânia') with those of the silage of monocropped corn, as well as to evaluate the pasture established in the intercropping systems during two growing seasons (2010-2011 and 2011-2012), in low-altitude Brazilian Cerrado. The treatments consisted of three cropping systems: monocropped corn, corn intercropped with palisade grass, and corn intercropped with guinea grass, with four replicates. Intercropping decreased corn forage dry matter yield for silage; however, due to the addition of grass, total dry matter yield (corn + grass) was similar between treatments. Intercropping also did not negatively affect corn production components and morphological characteristics. The cropping systems provided silages with good nutritive values, and the inclusion of tropical forages increased the silage fiber contents. Intercropping corn with tropical perennial grasses is a viable option for producing large quantities of silage with good nutritive value. The forage yield (silage + pasture) of these intercropping systems is similar to that of monocropped corn in tropical regions and has the advantage of providing a pasture in the off-season.521637

Cycling of nutrients and silicon in pigeonpea and pearl millet monoculture and intercropping

In a no-tillage system, cover crops must be used that combine shoot dry matter production and nutrient recycling. The aim of this study was to evaluate shoot dry matter production, decomposition rate and macronutrient and silicon release from pigeonpea and pearl millet in monoculture and intercropping systems. A randomized block design was used with a 3 x 6 factorial arrangement, with four replications. The first factor consisted of three cover crops (pigeonpea, pearl millet and intercropping of these cover crops) and the second consisted of six sampling times [0, 18, 32, 46, 74 and 91 days after desiccation (DAD)]. Pearl millet produced greater amounts of shoot dry matter and content of N, P, K, Ca, Mg, S, C and Si and had a higher decomposition rate and macronutrient and Si release than the other cover crops. The rates of decomposition and daily nutrient release from shoot dry matter were highest in the first period of evaluation (0-18 DAD). Over time, the C/N, C/P and C/S ratios increased, while C/Si and the decomposition rate decreased. Potassium was the nutrient most quickly released to the soil, especially from pearl millet residue. Silicon had the lowest release rate, with 62, 82 and 74 % of the total content in the shoot dry matter remaining in the last evaluation of pearl millet, pigeonpea and in the intercrop system, respectively. The shoot dry matter from the intercrop system had a different decomposition rate than that from the pearl millet monoculture and pigeonpea. Plants with greater shoot dry matter production and lower C/Si ratio are more effective in a no-tillage system for providing a more complete and persistent soil cover.As características mais importantes na escolha de plantas de cobertura para o sistema plantio direto são a quantidade e a durabilidade da fitomassa produzida, bem como a capacidade de reciclar nutrientes. Este estudo objetivou avaliar a produção de fitomassa, taxa de decomposição e ciclagem de macronutrientes e silício pelo guandu-anão e milheto, em cultivo solteiro e consorciado. O delineamento experimental foi em blocos casualizados, com quatro repetições, em esquema fatorial 3 x 6, constituído por três tipos de cobertura vegetal (guandu-anão, milheto e o consórcio dessas espécies) e seis épocas de coleta [0, 18, 32, 46, 74 e 91 dias, após a dessecação (DAD)]. O milheto produziu maior quantidade de fitomassa, acumulou mais N, P, K, Ca, Mg, S, C e Si e teve maior taxa de decomposição e de liberação de macronutrientes e Si que as demais coberturas vegetais. As maiores taxas de decomposição e liberação diária de nutrientes das fitomassas ocorreram no primeiro período de avaliação (0 a 18 DAD). Com o passar do tempo ocorreu aumento das relações C/N, C/P e C/S e redução na relação C/Si e na taxa de decomposição da fitomassa. O K foi o nutriente mais rapidamente disponibilizado ao solo, especialmente pela fitomassa do milheto. O Si foi o elemento que teve a menor taxa de liberação, restando na última avaliação 62, 82 e 74 % do total acumulado na fitomassa, respectivamente de milheto, guandu-anão e consórcio. A taxa de decomposição da fitomassa do consórcio milheto e guandu-anão foi diferente da proveniente dos cultivos solteiros. Plantas com maior produção de fitomassa e com menor relação C/Si são mais interessantes para utilização no SPD, por proporcionarem maior e mais persistente cobertura do solo.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)São Paulo State University College of Agricultural Sciences Department of Crop ScienceUNESP FCAUNESP FCA Department of Crop ScienceSão Paulo State University College of Agricultural Sciences Department of Crop ScienceUNESP FCAUNESP FCA Department of Crop ScienceFAPESP: 04/10361-

Produção de fitomassa e acúmulo de nutrientes por plantas de cobertura e cultivo da mamona em sucessão no sistema plantio direto

Objetivou-se avaliar a produção de matéria seca (MS) e o acúmulo de nutrientes pela crotalária (Crotalaria juncea L.) e pelo milheto (Pennisetum glaucum (L.) R. Brown), em cultivos isolado e consorciado, e o efeito do manejo mecânico da palhada no desempenho da cultura da mamona (Ricinus communis L.), em sucessão, na fase de implantação do sistema plantio direto. O experimento foi instalado em um Nitossolo Vermelho (Rhodic Kandiudox), em Botucatu, São Paulo (SP) (22°58'S, 48°23'W e 765m de altitude). O delineamento utilizado foi o de blocos casualizados, em parcelas subdivididas, com quatro repetições. As parcelas foram constituídas por três coberturas vegetais: crotalária - cultivar 'IAC-KR1'; milheto - cultivar 'BN 2'; e consórcio crotalária + milheto. As subparcelas foram constituídas pela ausência e presença do manejo mecânico da palhada com triturador horizontal 20 dias após o manejo químico. O milheto produziu maior quantidade de MS e apresentou maiores teores de K, Mg e S na parte aérea, enquanto a crotalária apresentou maiores teores de N e Ca. O milheto acumulou mais N, P, K, Mg e S na parte aérea, enquanto a crotalária acumulou maior quantidade de Ca. A produtividade de grãos da mamoneira foi maior em sucessão ao consórcio crotálaria + milheto e na ausência do manejo mecânico da palhada.The objective of this study was to evaluate aboveground matter production and nutrients accumulation by sunnhemp (Crotalaria juncea L.) and pearl millet (Pennisetum glaucum (L.) R. Brown), in sole crop and intercropped, and the effect of straw mulch mechanical management on castor bean (Ricinus communis L.) performance, in notillage system establishment. The experiment was carried out on a Rhodic Kandiudox, in Botucatu, SP, Brazil (22°58'S, 48°23'W and 765m above sea level). A randomized block design, in a splitplot scheme, with four replications, was used. The plots were composed by three cover crops: sunnhemp - cv. 'IAC-KR1'; pearl millet - cv. 'BN 2'; and intercropping - sunnhemp + pearl millet. The subplots were composed by absence or presence of straw mulch mechanical management, by horizontal crusher use, 20 days after chemical management. Pearl millet sole crop produced greater dry matter and showed higher K, Mg, and S concentration in aboveground, 75 days after emergence, while N and Ca concentration were higher in sunnhemp. Pearl millet sole crop accumulated greater amounts of N, P, K, Mg, and S, in aboveground, while sunnhemp accumulated elevated amount of Ca. Castor bean grain yield was higher in succession to sunnhemp + pearl millet intercropping and in the absence of straw mulch mechanical management

Upland rice yield as affected by previous summer crop rotation (soybean or upland rice) and glyphosate management on cover crops

The appropriate chemical management of cover crops in no-tillage aims to obtain greater benefits with its employment in agricultural systems. The objective of this study was to assess upland rice yield as affected by the previous summer crop, species and desiccation timing of cover crops by glyphosate. Sown cover crops were sown (November 2007), followed by rice in half of the experimental area and soybean in the other half (November 2008). After the harvesting of these crops, the same cover crops were sown again (March 2009) and followed by upland rice in the total area (November 2009). The experiment consisted of the combination of five cover crops (fallow, Panicum maximum, Brachiaria ruziziensis, B. brizantha and Pennisetum glaucum), four desiccation timings (30, 20, 10 and 0 days before rice sowing), and two antecedents of the summer crop (rice or soybean) under no-tillage system (NTS), plus two control treatments at conventional tillage system (CTS). Cover crops significantly affect rice grain yield and its components. There is a significant tendency to highest yield when cover crop desiccation is conducted farther from the rice sowing date (from 2,577.1 kg ha-1 - desiccation at rice sowing to 3,115.30 kg ha-1 - desiccation 30 days before rice sowing). Soybean as an antecedent of summer crop allows better upland rice yield (3,754 kg ha-1) than rice as an antecedent of summer crop (2,635 kg ha-1); fallow/soybean/fallow (4,507 kg ha-1) and millet/soybean/millet (4,765 kg ha-1) rotation at no-tillage system, and incorporated fallow /soybean/ incorporated fallow (4,427 kg ha-1) at conventional tillage system allow the highest rice yield; upland rice yield is similar at no-till (3,194 kg ha-1) and till system (2,878 kg ha-1).O correto manejo químico das plantas de cobertura visa obter maiores benefícios com a sua introdução nos sistemas agrícolas. O objetivo deste estudo foi avaliar como a produção do arroz de terras altas é afetada pela safra de verão anterior, pela espécie e pela época de dessecação das plantas de cobertura por glifosato. Foram semeadas plantas de cobertura (novembro de 2007), seguidas pelo arroz em metade da área experimental e soja na outra metade (novembro de 2008); após a colheita dessas culturas, as mesmas plantas de cobertura foram semeadas novamente (março de 2009), seguidas pela semeadura do arroz de terras altas (novembro de 2009) em toda a área experimental. Assim, o experimento consistiu na combinação de cinco plantas de cobertura (pousio, Panicum maximum, Brachiaria ruziziensis, B. brizantha e Pennisetum glaucum) x quatro épocas de dessecação (30, 20, 10 e 0 dias antes da semeadura do arroz) e dois antecedentes da safra de verão (arroz ou soja) no sistema plantio direto (SPD), mais dois tratamentos controle no sistema convencional (SC). As culturas de cobertura alteram significativamente a produtividade de grãos do arroz de terras altas e seus componentes. H�� tendência significativa de se obter maior produtividade do arroz quando a dessecação das culturas de cobertura é feita mais distante da época de semeadura de arroz (de 2.577,1 kg ha-1, dessecação realizada no dia da semeadura, para 3.115,3 kg ha-1, dessecação realizada 30 dias antes da semeadura do arroz). Soja como safra de verão anterior permite maior produção de arroz de terras altas (3.754 kg ha-1) do que arroz como antecedente de safra de verão (2.635 kg ha-1). Rotação pousio/soja/pousio (4,507 kg ha-1) e milheto/soja/milheto (4,765 kg ha-1) no plantio direto e pousio incorporado/soja/pousio incorporado (4,427 kg ha-1) no sistema de plantio convencional permitiram maior produção de arroz; a produtividade do arroz é semelhante em plantio direto (3,194 kg ha-1) e em plantio convencional (2,878 kg ha-1)