Phosphogypsum applied in surface and mixed at soil on hydraulic conductivity, pH and leaching of sodium of one saline sodic soil

Samples of a saline-sodic soil (of the Irrigated Perimeter of São Gonçalo, Souza towm, Paraiba State - Brazil) that has 61.25 me/100 of exchangeable sodium, were collected at depth 0-30 cm and phosphogypsum was applied in two levels (50% and 100% of the gypsum requirement - GR of the soil). The study v;as realized with the soil put in column of paltic tuble of 40 cm of tall and 5 cm of diametr. Both the quantities of the phosphogypsum (31 g (level-50% GR) and 62 g (level-100% GR)) were applied in the surface of the soil and too incorporated at depth 0-15 in such column. The water volume applied was 314 me and the time for star and the finish the leaching was read for to evaluate the hydraulic conductivity. In the end of the leaching each column was dismonted and divided in six parts of 5 cm that were made saturation extracts (1:5) of where were determinated pH, electric conductivity, soluble sodium content and the remaining sodium percentage (RSP). The data evidencied positive effects of the phosphogypsum on hydraulic conductivity of the soil, especially when the chemical corretive was incorporeted at 15 cm under surface of the soil. The hydraulic conductivity (k) valours showed that the less level (50% GR) was more efficient than great level (100% GR of the soil). The data of k for the phosphogypsum incorporated were 2.45 cm/h (level-50% GR) and 1.41 cm/h to level 100% of the gypsum requirement of the soil. In spite the chemistry aspects the electric conductivity data, soluble sodium contents and calours of remaining sodium percentage (RSP) of each interval of 5 cm of the columns , indicated that the phosphogypsum were more efficient in the displacement of exchangeable sodium when it was appliaed in the susrface of the soil. This way the chemical corretive showed to exercise differenced behaviour on physical and chemical properties of the soil alike its way of applications at soil.O trabalho foi realizado com amostras de um solo salino sódico do Perímetro Irrigado de São Gonçalo - Souza-PB, coletadas a 30 cm de profundidade. As amostras foram acondicionadas em tubos de polietileno com 5 cm de diâmetro e 40 cm de altura, com capacidade para um quilo de terra. Em função do teor de sódio trocável determinou-se a necessidade de gesso e foram aplicadas 32 g (dose-1) e 64 g (dose-2) de fosfogesso da Ultrafértil na superfície e incorporadas de 0 a 15 cm de superfície. Essas doses correponderam a 50 e 100% da exigência máxima de gesso pelo solo. Em seguida aplicou-se água correspondente ao volume de poros, registrou-se o tempo inicial e final de lixiviação e o volume drenado nesse período para o cálculo da condutividade hidraulica. Após cessar a lixiviação as colunas foram desmontadas e divididas em seis amostras de 5 cm, de onde determinou-se o pH, condutividade elétrica, teor de sódio solúvel do extrato de saturação 1:5 e a percentagem de sódio remanescente. Os resultados evidenciaram efieots positivos do gesso industrial (fosfogesso ) na capacidade de transmissão de água,especialmete quando incorporado na proporção de 50% (dose-1) da necessidade de gesso do solo. Em relação a condutividade hidráulica o fornecimento do corretivo foi .mais eficiente quando incorporado do que quando aplicado na superfície do solo. Do ponto de vista químico, os valores de condutividade elétrica, teores de sódio do extrato de saturação e percentagem de sódio remanescente de cada um dos intervalos, indica ram que o fosfogesso foi mais eficiente na lixiviação de sais quando aplicado na superfície. Pelo exposto, o modo de aplicação do fosfogesso mostrou exercer comportamento diferenciado entre as características físicas e químicas do solo, para uma única lixiviação

Biofertilizers in horticultural crops

Bovine manure biofertilizers can exert physical, chemical, and biological effects on the soil and the phytoprotective, physiological, and productive actions in horticultural crops. The literature review was performed to compile information on the production, uses, and effects of bovine manure biofertilizers on soil properties and plants. Biofertilizers are produced by organic components, minerals, and inoculants. Among the organic sources, the bovine manure is the most used. The fermentation of the bovine manure in water constitutes the Vairo biofertilizer, the most employed in Brazilian horticulture. With the chemical enrichment of this preparation came the Supermagro, Agrobio, and Agrobom biofertilizers. In the soil, it can act in the improvement of soil fertility, physical properties, and in the diversity and abundance of the biota. Also, it can act in control of pests and diseases, leaf composition concerning macro and micronutrients, and in the production and post-harvest quality of horticultural crops. Therefore, this review describes the preparation, chemical composition, and utilization of bovine manure biofertilizers in both soil and plants, offering perspectives of research on the formulations, application, and effects of these inputs on horticultural species.Bovine manure biofertilizers can exert physical, chemical, and biological effects on the soil and the phytoprotective, physiological, and productive actions in horticultural crops. The literature review was performed to compile information on the production, uses, and effects of bovine manure biofertilizers on soil properties and plants. Biofertilizers are produced by organic components, minerals, and inoculants. Among the organic sources, the bovine manure is the most used. The fermentation of the bovine manure in water constitutes the Vairo biofertilizer, the most employed in Brazilian horticulture. With the chemical enrichment of this preparation came the Supermagro, Agrobio, and Agrobom biofertilizers. In the soil, it can act in the improvement of soil fertility, physical properties, and in the diversity and abundance of the biota. Also, it can act in control of pests and diseases, leaf composition concerning macro and micronutrients, and in the production and post-harvest quality of horticultural crops. Therefore, this review describes the preparation, chemical composition, and utilization of bovine manure biofertilizers in both soil and plants, offering perspectives of research on the formulations, application, and effects of these inputs on horticultural species