Influence of hydrogel use on soybean cultivation hydrical stress / Influência do uso do hidrogel no cultivo da soja sob estresse hídrico

Among the agricultural production factors, the water deficit is one of the main reasons that limits soy production in Brazil. In order to mitigate losses due to water stress in the plants, hydrogels appear as soil water conditioners. They are polymers capable of absorbing large amounts of water and are being used as a viable alternative to improve the storage of water in areas of scarcity. Hydrogen concentrations between 14 and 18 kg ha-1 resulted in higher plant height, number of pods, one hundred grain mass and grain yield.

Dentre os fatores de produção agrícola, o déficit hídrico é um dos principais motivos que mais limita a produção de soja no Brasil. A fim de amenizar os prejuízos por estresse hídrico nas plantas, os hidrogéis surgem como condicionadores de água no solo, já são polímeros capazes de absorver grande quantidade de água e estão sendo utilizados como alternativa viável para melhorar o armazenamento de água em áreas de escassez. Objetivou-se com este trabalho avaliar a eficiência da utilização do hidrogel na retenção e disponibilização de água para o desenvolvimento e produção da cultura da soja quando submetido a estresse hídrico. As concentrações de hidrogéis entre 14 e 18 kg ha-1 resultaram em maior altura de plantas, número de vagens, massa de cem grãos e produtividades de grãos.

Macroalgae as Soil Conditioners or Growth Promoters of Pisum sativum (L)

Mexico has long littorals that receive great amounts of marine algae that are wasted despite being potentially useful as growth promoters without the inconveniences of agrochemicals. Some macroalgae have been used with excellent results as soil conditioners and fertilisers in agriculture. In this study nine macroalgae from the coasts of Veracruz (Gulf of Mexico) and one from Guerrero (Mexican Pacific), Mexico, were tested. They were added to the soil in the form of fragments and of silage in liquid around Pisum sativum plants. A two-way random design with four replicas was followed. Two controls, hormones and water, were also used. Growth was recorded every third day. Results showed that four algae promoted growth (p<0.05) Ulva fasciata (ensiling treatment) and Ulva lactuca (ensiling treatment) and Gracilaria caudata (fragment treatment) and Palisada perforata (fragment treatment), compared with the hormones and water controls. The activity of Ulva fasciata and Palisada perforata is recorded for the first time. Since the control plants treated with hormones grew much less than those treated with the four algae, we conclude that the release of all algae compounds was responsible for the growth, and not the hormone mimetics.

Effect of Spent Mushroom Compost of Pleurotus pulmonarius on Growth Performance of Four Nigerian Vegetables

Spent mushroom compost (SMC) of Pleurotus pulmonarius (an edible fungus) was used as soil conditioner for the improvement of growth of four common Nigerian vegetables (Abelmoschus esculentus, Lycopersicum esculentum, Capsicum annum and Capsicum chinense). The results of these investigations showed that the vegetables responded well to the SMC treatment. Each of them attained its best growth and gave the highest number of flowers and fruits when planted on 6 kg of depleted garden soil supplemented with 600 g of SMC. The control experiment that has the seedlings of the vegetables planted on 6 kg of depleted garden soil only, without the application of SMC, showed stunted and poor growth, with few or no flower and fruit production. A. esculentus was the best utilizer of iron utilizing 118.0 mg/kg in the SMC used. Similarly; this vegetable utilized 1.48 mg/kg of nitrogen in the SMC. The highest height in each vegetable was attained with 6 kg of depleted garden soil supplemented with 600 g of SMC. At 9 wk, A. esculentus has the mean height of 85.0 cm while these values significantly increased to 100.00 cm at 14 wk (p < or = 0.05). At 9 wk, L. esculentum has the highest mean height of 65.00 cm which increased to 71.00 cm after 14 wk. It was also observed that A. esculentus has the highest mean number of fruits (9.00), followed in order by C. chinense (8.00) and L. esculentus (7.00) (p < or = 0.05) while, C. annum produced the least mean number of fruits (5.00). No fruits production was seen in the control experiments. The results of these findings were discussed in relation to the usage of SMC as possible organic fertilizer for the improvement of growth of vegetables in Nigeria.