Although silicon is not recognized as a nutrient, it may benefit rice plants and may alleviate the Mn toxicity in some plant species. The dry matter yield (root, leaf, sheaths and leaf blade) and plant architecture (angle of leaf insertion and leaf arc) were evaluated in rice plants grown in nutrient solutions with three Mn doses, with and without Si addition. The treatments were arranged in a 2 x 3 factorial [with and without (2 mmol L-1) Si; three Mn doses (0.5; 2.5 and […]

Zeolites are hydrated crystalline aluminosilicate minerals of natural occurrence, structured in rigid third dimension net that can be used as slow release plant-nutrient source. The main objective of this study was to evaluate the effects of plant growth substrate under zeolite application, enriched with N, P and K, on dry matter yield and on nutrient contents in consecutive crops of lettuce, tomato, rice, and andropogon grass. The experiment was carried out in a greenhouse, with 3 kg pots with an […]

Losses of productivity of flooded rice in the State of Rio Grande do Sul, Brazil, may occur in the Coastal Plains and in the Southern region due to the use of saline water from coastal rivers, ponds and the Laguna dos Patos lagoon, and the sensibility of the plants are variable according to its stage of development. The purpose of this research was to evaluate the production of rice grains and its components, spikelet sterility and the phenological development of […]

The low capacity to predict potassium (K) availability for rice by different evaluation methods is due to the greater potassium diffusion in the flooded soil solution and to potassium supply through non-exchangeable forms in the soil. The purpose of this study was to evaluate the supply capacity of exchangeable and non-exchangeable potassium forms by flooded soils with different characteristics, in successive rice crops. Rice plants were grown in a greenhouse in 12 dm3 pots in three soils (Typic Hapludales, Aquic […]

The Depressão Central region in the State of Rio Grande do Sul, Brazil, is characterized by large areas of sandy soil that were intensively cultivated with flooded rice in the last decades. Currently, the high rice yields, along with the low organic matter content of these soils and the fertilization practices are favorable conditions for the appearance of sulfur (S) deficiency. With the purpose of determining sulfur distribution in the soil profile and recommending levels of this element for flooded […]

The use of water for rice irrigation in Rio Grande do Sul, Brazil, where the water courses are connected with the sea, may cause salt accumulation in the soil at harmful levels for the establishment of rice plants in the following years, especially when high rates of potassium fertilizer are applied in the plant rows. The study was carried out with the purpose of evaluating the effect of potassium chloride management on the establishment and absorption of cations by rice […]

Appropriate boron (B) availability in soils favors root growth, and a sufficient supply of this micronutrient is very important for adequate rice development and yield in upland fields, depending on the cultivars and soil type. This study aimed at evaluating the influence of B addition on growth of roots and shoot of three upland rice cultivars. The experiment was carried out in a greenhouse, in 10 L pots containing 8 kg of an Hapludox; the experiment was in a completely […]

The aim of this study was to quantify the contribution of soluble organic-C deposition by rice root system and the CO2 evolution during 64 days in an Oxisol samples treated with glucose, and rice roots collected at different plant growth stages (40, 60, 80, 100, 120 and 140 days after sowing). Thereafter, organic matter was fractionated to evaluate the effect of the addition of a root system on the soil humus composition. It was possible to observe the intense rhizodeposition of organic […]

The presence of heavy metals can restrict the use of sewage sludge as a source for plant nutrients since they may contaminate soil, aquifers and plants. Urban sewage sludge from the Treatment Station of Ilha do Governador (ETIG), Rio de Janeiro, Brazil, was enriched with 1.667 mg kg-1 Cd and 8.000 mg kg-1 Zn. After 20 days of incubation under a constant humidity of 50% (g g-1), doses of 0, 20, 40 and 80 t ha-1 were applied to two soil samples (red-yellow Latosol (LV) and red-yellow Argisol […]

Pot experiments are being used to study the potassium supplying capacity of soils. A greenhouse experiment with this objective evaluated samples of two Planosols, a Chernosol and a Gleisol, where flooded rice did not respond to potassium fertilization. The soils were cropped during 50 days with rice (Oriza sativa – BR-IRGA 409). Potassium uptake by the plant shoot, the exchangeable and non-exchangeable soil K, extracted by NH4OAc 1 mol L-1 and boiling HNO3 1 mol L-1, respectively, were evaluated, before […]