Impact of water saving irrigation systems on water use, growth and yield of irrigated lowland rice

To meet the growing demand for food and other needs from an increasing population, the rice production in Sri Lanka, which was 3.87 million tonnes in 2008, has to be increased to 4.2 million tonnes by the year 2020. This requirement could be achieved by increasing productivity and/or by increasing the cultivated extent. In 2008, about 77 % and 68 % of the total paddy land extent was cultivated with either partial or full irrigation during the maha and yala seasons, respectively. A considerable extent of paddy land was either not cultivated or cultivated for other crops due to the scarcity of water in the dry and intermediate zones. Furthermore, with increased competition for water for domestic and industrial needs and climate change, there will be further reductions in the availability of water for rice cultivation. Conserving irrigation water would increase the cultivated extent of land while reducing the probability of ate season water-stress in the cultivated rice crop. We studied the impact of different soil water regimes on water use, nutrient uptake, growth and grain yield of 3 – 3� age lowland rice at the Rice Research and Development Institute, Batalagoda, Ibbagamuwa. There was no significant difference in the grain yield in rice when grown under either saturated or flooded conditions, but the yield decreased significantly with alternate wetting and drying. However, under saturated conditions, the irrigation water requirement was significantly lower than the flooded condition. The lowest irrigation water requirement was recorded with saturated to dry conditions. The irrigation water requirement under flooded conditions, when compared with the saturated condition, increased by 39 % during the yala season. During the maha season, even though the total irrigation requirement was lower, when compared to saturated conditions, four times more irrigation water was required under flooded conditions. There was a significant increase in plant dry matter production and leaf N (nitrogen) under saturated conditions, when compared with conventional flooded conditions. These findings suggest that when soil water is maintained at a saturated level in lowland rice, a considerable amount of irrigation water could be saved without sacrificing grain yield.Length: pp.57-64RiceIrrigated farmingWater conservationIrrigation systems

Regular string-like braneworlds

In this work, we propose a new class of smooth thick string-like braneworld in six dimensions. The brane exhibits a varying brane-tension and an $AdS$ asymptotic behavior. The brane-core geometry is parametrized by the Bulk cosmological constant, the brane width and by a geometrical deformation parameter. The source satisfies the dominant energy condition for the undeformed solution and has an exotic asymptotic regime for the deformed solution. This scenario provides a normalized massless Kaluza-Klein mode for the scalar, gravitational and gauge sectors. The near-brane geometry allows massive resonant modes at the brane for the $s$ state and nearby the brane for $l=1$.Comment: 14 pages, 12 figures. Some modifications to match the published version in EPJ

Irrigação do tomateiro para processamento.

O objetivo desta circular técnica é apresentar processos e informações técnicas atuais sobre os principais sistemas e métodos de manejo de irrigação disponíveis para a produção do tomate para processamento no Brasil.bitstream/item/60166/1/11-13-CT-102-Prova-2012-03-12.pd

Irrigação por aspersão em hortaliças: qualidade da água, aspectos do sistema e método prático de manejo.

Qualidade da água para irrigação; aspectos físicos; aspectos químicos; aspectos sanitários; Relação solo-água-planta-clima; Disponíbilidade de água no solo; Necessidade de água das plantas; Irrigação por aspersão; Sistemas convencionais; Autopropelido tipo carretel enrolador; Pivô central; Eficiência de irrigação; Sistemas por aspersão convencional; Escolha do aspersor; Pressão do serviço do aspersor; Vazão de serviço; Raio de alcance do aspersor; Espaçamento entre aspersores; Intensidade de aplicação de água; Variação da pressão ao longo da lateral; Manutenção e cuidados com o sistema de irrigação; Manejo prático da água de irrigação; Fases da cultura; Evaporação da cultura; Tipo de solo; Profundidade efetiva do sistema radicular; Turno de rega; Lâmina de água real necessária; Tempo de irrigação; Prorrogação da irrigação em decorrência de chuvas; Período críticos; Manejo de água na fase inicial da cultura; Primeira irrigação; Irrigações subsequentes; Sementeira; Paralisação das irrigações; Considerações sobre o manejo de irrigação em tempo real; Associação da irrigação com doenças.bitstream/item/107361/1/CNPH-IRRIG.-POR-ASPER.-EM-HORT.-08.pdf2. ed. rev. atual. ampl

Achieving minimum-error discrimination of an arbitrary set of laser-light pulses

Laser light is widely used for communication and sensing applications, so the optimal discrimination of coherent states--the quantum states of light emitted by a laser--has immense practical importance. However, quantum mechanics imposes a fundamental limit on how well different coher- ent states can be distinguished, even with perfect detectors, and limits such discrimination to have a finite minimum probability of error. While conventional optical receivers lead to error rates well above this fundamental limit, Dolinar found an explicit receiver design involving optical feedback and photon counting that can achieve the minimum probability of error for discriminating any two given coherent states. The generalization of this construction to larger sets of coherent states has proven to be challenging, evidencing that there may be a limitation inherent to a linear-optics-based adaptive measurement strategy. In this Letter, we show how to achieve optimal discrimination of any set of coherent states using a resource-efficient quantum computer. Our construction leverages a recent result on discriminating multi-copy quantum hypotheses (arXiv:1201.6625) and properties of coherent states. Furthermore, our construction is reusable, composable, and applicable to designing quantum-limited processing of coherent-state signals to optimize any metric of choice. As illustrative examples, we analyze the performance of discriminating a ternary alphabet, and show how the quantum circuit of a receiver designed to discriminate a binary alphabet can be reused in discriminating multimode hypotheses. Finally, we show our result can be used to achieve the quantum limit on the rate of classical information transmission on a lossy optical channel, which is known to exceed the Shannon rate of all conventional optical receivers.Comment: 9 pages, 2 figures; v2 Minor correction