The no-tillage system and cover crops-Alternatives to increase upland rice yields

Upland rice (Oryza sativa L.) cultivation has been increasing in importance in Asia while water availability for irrigation has been decreasing because of rapid growth in industry and urban centers. Therefore, the development of technologies that increase upland rice yields under aerobic conditions, thereby saving water, would be an effective strategy to avoid a decrease in global rice grain production. The use of the no-tillage system (NTS) and cover crops that maintain soil moisture would prove advantageous in the move toward sustainable agriculture. However, upland rice develops better in plowed soil, and it has been reported that this crop does not perform well under the NTS. Therefore, the aim of this study was to investigate the effect of cover crops on upland rice grain yield and yield components sowed in a NTS. A field experiment was conducted during two growing seasons (2008-2009 and 2009-2010), and treatments consisted of growing rice under five cover crops in a NTS and two control treatments under the conventional tillage system (plowing once and disking twice). Treatments were carried out in a randomized block design with three replications. Our findings are as follows: On average, Brachiaria brizantha (12.32Mgha-1), Brachiaria ruziziensis (11.08Mgha-1) and Panicum maximum (11.62Mgha-1) had outstanding biomass production; however, these grasses provided the worst upland rice yields (2.30, 2.04, and 2.67Mgha-1, respectively) and are not recommended as cover crops before upland rice. Millet and fallow exhibited the fastest straw degradation (half-lives of 52 and 54 days, respectively), and millet exhibited the fastest nitrogen release (N half-life of 28 days). The use of a NTS was promising when millet was used as a cover crop; this allowed the highest upland rice yield (3.94Mgha-1) and did not statistically differ from plowed fallow (3.52Mgha-1). © 2012 Elsevier B.V.

Response of rice cultivars to nitrogen in upland conditions

Against the background of a growing world population, rice (Oryza sativa L.) consumption is expected to grow faster than its production. Therefore, an appropriate question would be: how to increase productivity in the shortterm? In this respect, it becomes important the implementation of modern agricultural production systems, such as upland rice with supplemental sprinkler irrigation. Additional information is needed to maximize the available resources, with special attention given to research on the use of nitrogen. This study aimed to evaluate the agronomic performance of commercial rice cultivars with different plant characteristics in upland conditions with supplemental sprinkler irrigation, when subjected to nitrogen in topdress application at the R1 stage (panicle differentiation). The experiment was arranged in a randomized block with split plot design, with 65 treatments, consisting of the combination of 13 cultivars in the plots, and five nitrogen levels in the subplots (0, 40, 80, 120 and 160 kg ha-1), with four replications. Genetic variability was detected among rice cultivars and the agronomic performance in response to the applied nitrogen. The topdressing application of nitrogen increases, in general, the production components and grain yield in rice. Cultivars BRS Primavera, Caiapó and IAC 202 stood out for grain yield, followed by Baldo, Carnaroli, BRS Curinga and IAC 500 with lower yields.

Resposta da alface à aplicação de biofertilizante sob dois níveis de irrigação

The use of biofertilizers is interesting for agriculture as being an economical alternative as well as it is environmentally friendly by using organic waste and reducing the application of mineral fertilizers. The aim of this study was to evaluate the effect of biofertilizer doses of bovine origin (biodigester effluent) applied on the ground and two levels of irrigation on lettuce. The experiment was conducted under protection of a greenhouse in pots, applying to the soil different doses of biofertilizer of bovine origin obtained from anaerobic reactor (10, 20, 40 and 60 m3 ha-1) and mineral fertilizer as a witness in two irrigation levels calculated at 50 and 100% of reference evapotranspiration. The lettuce plants were analyzed in their: Height, leaves number, crown diameter, fresh weight and dry weight of shoots. The biofertilizer treatments showed better results than the mineral fertilizer and has increased with increasing doses of biofertilizer, the highest dose (60 m3 ha-1) showed the best results in all variables. For dry, mineral fertilization showed higher values. The irrigation levels had no effect on plant growth.

Cover crop termination timing on rice crop production in a no-till system

Measuring shikimic acid accumulation in response to glyphosate applications can be a rapid and accurate way to quantify and predict glyphosate-induced damage to sensitive plants. The objective of this paper was to evaluate the effect of cover crop termination timing by glyphosate application on rice (Oryza sativa L.) yield in a no-till system. A factorial experiment, arranged in a split-plot design, was conducted for 2 yr. Treatments consisted of cover crops (main plots) and timed herbicide applications (subplots) to these cover crops (30, 20, 10, and 0 d before rice planting). There was a decrease in rice yield from 2866 kg ha-1 to 2322 kg ha-1 when the herbicide was applied closer to the rice planting day. Glyphosate application on cover crops increased shikimate concentrations in rice seedlings cultivated under palisade grass (Brachiaria brizantha), signal grass (B. ruziziensis), guinea grass (Panicum maximum), and weedy fallow (spontaneous vegetation) but not under millet (Pennisetum glaucum), which behaved similarly to the control (clean fallow, no glyphosate application). Glyphosate applications in the timing intervals used were associated with stress in the rice plants, and this association increased if cover crops took longer to completely dry and if higher amounts of biomass were produced. Millet, as a cover crop, allowed the highest seedling dry matter for upland rice and the highest rice yield. Our results suggest that using millet as a cover crop, with glyphosate application far from upland rice planting day (10 d or more), was the best option for upland rice under a no-tillage system. © Crop Science Society of America.

Desempenho de cultivares transgênicas de soja em sucessão a culturas de inverno em semeadura direta

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Silício na tolerância ao alumínio por plantas de arroz

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de plantas de arroz sob a ação de silício e nitrogênio

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cinética de absorção de silício por cultivares de cana-de-açúcar e de arroz

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interação de progênies de alface do grupo americano por épocas de cultivo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Composição química de águas residuárias provenientes de efluentes urbanos destinadas à irrigação

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Incorporação de biofertilizante no solo sob dois níveis de irrigação e em dois ambientes distintos no desenvolvimento da planta de alface

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Levantamento de raças de Bremialactucae em 2011 nas principais áreas produtoras de alfaces do Estado de São Paulo e avaliação da resistência em cultivares comerciais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reação de aveia branca, feijão, sorgo e trigo a Meloidogyne incognita, M. javanica e M. enterolobii

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Investigação de efeitos alelopáticos de espécies do gênero Arachis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Manejo do solo e da adubação nitrogenada em arroz de terras altas irrigado por aspersão

Pós-graduação em Agronomia - FEIS