Em determinadas condições de relevo, do clima e de uso, com certa frequência pode acontecer acúmulo de sais nos solos, dando lugar à formação dos solos salinos e sódicos - também denominados de solos afetados por sais. A fim de orientar as práticas de manejo e uso das terras da região do Baixo Acaraú, CE, objetivou-se com o presente trabalho gerar um mapa de risco de salinização. Para obtenção das classes de vulnerabilidade, foram avaliados os temas pedologia, geologia, geomorfologia e uso e cobertura das terras e informações de declividade e altimetria, tratados em ambiente SIG com o método multicritério aditivo. Foram definidas quatro classes de risco de salinização: baixo, moderado, alto e altíssimo ou solos naturalmente salinos/sódicos. Foi constatado que 35,47 % da área corresponde à classe de baixo risco de salinização; 26,22 %, à de risco moderado; 8,23 %, à de risco alto; e 19,65 %, à de risco altíssimo.

This study aimed to evaluate the nutritional quality of Pilosocereus gounellei using different methods of spine removal and plant storage. A total of 600 P. gounellei cacti were randomly selected in 10 hectares of Caatinga. The experimental design was completely randomised using a 2 x 4 factorial arrangement and three replicates. The variables evaluated were the storage conditions (under trees; and ventilated storage facilities) and four types of spine removal techniques assessed 31 days after storage (fresh plants with spines [control]; use of flamethrowers before storage; slash-and-burn [“coivara”] before storage; and use of flamethrowers after storage). The P. gounellei subjected to slash-and-burn during the cladode harvest (cutting) process deteriorated rapidly and exhibited a smooth consistency; dark colour. The burning process resulted in increased in situ degradability of dry matter compared with the control treatment. The results of treatment 4 were similar to those of the control treatment regarding the preservation of the nutritional properties of P. gounellei. Therefore, P. gounellei can be harvested and stored fresh for 31 days without losing their nutritional properties, and spines should be removed using flamethrowers after the storage period, i.e., when using the plants as livestock feed.

Cactus pears face challenges due to global climate change, which is leading to in-depth research to monitor and increase their water activity. The objective of this study was to evaluate the use of the natural test hydrogel (TH) from Orbignya phalerata fibre as nutrients and water for growing cactus pear genotypes (“Baiana” and “Doce” [Nopalea cochenillifera], ‘Gigante’ [Opuntia fícus-indica], and “Mexican Elephant Ear” [Opuntia stricta]) compared to the use of commercial hydrogel (CH), which is based on polymers composed of polyacrylamide, and a treatment without the use of hydrogel (WH). A completely randomized design was used, in a factorial scheme (4 × 3), with four genotypes of cactus pear and three forms of hydration, with five replications. The number and area of cladode was greatest (p < 0.01) in plants with CH and TH irrigation-fertilization in the ‘Doce’ cactus genotype. The dry biomass of the cladode and root in the ‘Gigante’ cactus genotype was greatest (p < 0.01) in the treatments with CH and TH irrigation-fertilisation. The ‘Baiana’, ‘Doce’, and ‘Gigante’ cactus genotypes exhibited more (p < 0.01) dry matter content with the TH irrigation-fertilisation. The highest (p < 0.01) neutral detergent fibre content was observed in the ‘Baiana’ and ‘Doce’ cactus genotypes when irrigation occurred with WH treatment, and the highest acid detergent fibre content in the ‘Gigante’ genotype. The copolymerized natural fibre from the mesocarp of Orbignya phalerata (babassu fruit) induced a better growth and chemical composition of cactus pear genotypes than the hydrogel based on polymers composed of polyacrylamide.

²Departamento de Zootecnia-UFC. Bolsista do CNPq. 2 Departamento de Zootecnia do CCA/UFC ________________________________________________________________________ Resumo: No presente trabalho serão abordadas as plantas tóxicas de interesse, pecuário, isto é, plantas que tiveram a toxicidade comprovada através de experimentos com espécies de animais domésticos. São classificadas como plantas tóxicas de interesse pecuário as espécies que em condições naturais causam intoxicação nos animais. Neste sentido, nem todas as plantas demonstradas experimentalmente como tóxicas devem ser consideradas plantas tóxicas de interesse pecuário por não produzirem quadros clínico-patológicos sob condições naturais. Essas plantas causam grande prejuízo ao produtor podendo ser com perdas diretas onde são rapidamente identificados ocorrendo morte, redução do crescimento, perda de peso, problemas reprodutivos tais como abortamentos, malformações e menor taxa de concepção; podendo acarretar também perdas indiretas como a construção de cercas, alterações no manejo e gastos médicos.

Cactus pear is an important species for animal feeding in the regions of dry climate. There is no information on the fertilization with coated urea in the cultivation of cactus pear under rainfed conditions in the savannah region. The aim of the current study was to evaluate the forage potential of Nopalea cochenillifera variety Doce in yellow latosol under rainfed conditions in the Brazilian savannah, comparing the fertilization with urea and coated urea in different levels. A randomized block design was adopted, in a 2 × 4 × 2 factorial scheme, with the factors corresponding to two sources of nitrogen (urea and urea coated with polymers, N+), four levels of nitrogen (0, 60, 120 and 240 kg/ha/year) and two harvests (year I and year II). The plants were evaluated after 1 year of growth, in each year of evaluation, regarding the characteristics of growth, production, chemical and mineral composition and nutritional value. The level of 240 kg/ha provided higher emission of cladodes per plant (17.33 and 18.17), respectively, for N+ and urea. The highest nitrogen use efficiency was found in the level of 60 kg N/ha (142 kg/ha/year). NFC values were 3.5 g/kg dry matter (DM) higher when the cactus pear was fertilized with urea in year I and 5.4 g/kg DM in year II. The use of conventional urea promoted better results of agronomic and nutritional characteristics of the cactus pear, under rainfed regime, when compared to the use of urea coated with polymers.