Although inoculation of N2-fixing bacteria in cowpea is important, there are no studies on their performance in Itaueira, PI, Brazil. This work aimed to evaluate the symbiotic efficiency of nodulating bacteria strains officially approved by Ministério da Agricultura, Pecuária e Abastecimento, Brazil - MAPA (INPA 3-11B, UFLA 3-84, BR 3267 and BR 3262) and in phase of selection (UFLA 3-164 and UFLA 3-154) in the nodulation and growth of cowpea cultivar BR 17 Gurguéia in Itaueira, PI, Brazil. Experimental design was in randomized blocks with eight treatments and four replications, consisting of six strains cited and two non inoculated controls, one with N mineral (70 kg ha-1 of N) and other without N mineral. Nodulation, growth, yield and accumulation of N, P, K, Ca and Mg in shoots of cowpea beans were evaluated. Strains under test phase (UFLA 3-154 and UFLA 3-164) presented number of nodules, and fresh and dry biomass of nodules similar to strains currently approved as inoculants. Treatments inoculated with INPA 3-11B and BR 3267 strains were more efficient in dry biomass production of shoots. Plants inoculated with strains UFLA 3-164, INPA 3-11B and BR 3267 presented highest concentration of N, P, K, Ca, and Mg in dry biomass of shoots. Strains in selection phase (UFLA 3-164 and UFLA 3-154) presented similar grain yield among themselves, however the strain UFLA 3-154 obtained productivity equivalent to the nitrogen control and all strains evaluated. Inoculation of cowpea with strains BR 3262, BR 3267 and UFLA 3-154 promoted increments of cowpea productivity in Itaueira, PI, therefore they may be recommended for cultivation in this region

Highlights➢ A multivariate estimation of the environmental status of rehabilitating areas is presented ➢ The method integrates processes, diversity and structure in a single estimation ➢ Rehabilitation status is successfully estimated after iron ore mining in Corumbá ➢ The approach enables tests for biases regarding single variables or variable groups ➢ Defining indicators reduces the number of variables needed for further assessments AbstractDespite the wide variety of variables commonly applied to measure different aspects of rehabilitation, the assessment and subsequent definition of indicators of environmental rehabilitation status are not simple tasks. The main challenges are comparing rehabilitated sites with target ecosystems as well as integrating individual environmental and eventually collinear variables into a single tractable measure of the state of a system before effective indicators that track rehabilitation may be modeled. For that, a consensus is lacking regarding which and how many variables need to be surveyed. Our approach considered ecological processes, vegetation structure, and community diversity from nonrehabilitated, rehabilitating and reference sites. We applied this approach to a curated set of 32 environmental variables retrieved from nonrevegetated, rehabilitating and reference sites associated with iron ore mines from the Urucum Massif, Mato Grosso do Sul, Brazil. By integrating variables from a single attribute or the entire set of variables into a single estimation of rehabilitation status, the proposed multivariate approach is straightforward and able to adequately address collinearity among variables. The proposed approach allows for the identification of biases towards single variables, surveys or analyses, which is necessary to rank environmental variables regarding their importance to the assessment. Furthermore, we show that bootstrapping permitted the detection of the minimum number of environmental variables necessary to achieve reliable estimations of the rehabilitation status. Finally, we show that the proposed variable integration enables the definition of environmental indicators for more comprehensive monitoring of mineland rehabilitation. Thus, the

Pastures are important food sources for Brazilian cattle herds. However, inadequate management of soil fertility has emerged as a major cause of low yield rates and of progressive degradation of these areas. The objective of the present study was to evaluate growth, by means of morphogenetic and structural characteristics, and yield of Brachiaria brizantha Stapf. cv. Marandu as functions of the application of the mycorrhizae stimulant formononetin, associated with lime and phosphate application. The experimental design was completely randomised with four replications, and the treatments were arranged in a 2 x 2 x 5 factorial scheme, consisting of two liming treatments (with and without limestone), two formononetin treatments (with and without application) and five P 2 O 5 doses (0, 25, 50, 100 and 200 mg dm -3 ). Three shoot cuttings were carried out after a first standardisation cutting to evaluate the morphogenetic and structural characteristics as well as the dry matter yield of different morphological fractions. Liming and phosphate application at the dose of 141 mg dm -3 P 2 O 5 increased growth and yield of Marandu grass, and these practices are essential for the cultivation of this pasture grass in Yellow Latosol of the Cerrado region of Piauí, Brazil. The application of formononetin increased stem elongation rate, total number of tillers and green stem dry matter, and decreased dead dry matter of Marandu grass, which are effects that contribute to the improvement of pasture quality. Key words: Brachiaria brizantha. Mycorrhizae. Pastures. Soil acidity. ResumoAs pastagens constituem importante fonte alimentar para os rebanhos brasileiros, entretanto, o manejo inadequado da fertilidade dos solos têm-se destacado como uma das principais causas dos baixos índices produtivos e da progressiva degradação destas áreas. O objetivo do presente estudo foi avaliar o crescimento, através das características morfogênicas e estruturais, e a produção da Brachiaria brizantha Stapf. cv. Marandu em função da aplicação do estimulante de micorrização formononetina associado a calagem e a fosfatagem. O delineamento experimental adotado foi o inteiramente casualizado, com quatro repetições, sendo os tratamentos dispostos num esquema fatorial 2 x 2 x 5, constituídos por dois tratamentos de calagem (com e sem calcário), dois de formononetina (com e sem aplicação) e cinco doses de P 2 O 5 (0, 25, 50, 100 e 200 mg dm -3 ). Foram realizados três cortes da parte aérea, após um primeiro corte de uniformização, para realização das avaliações das características morfogênicas e estruturais, bem como a produção de massa seca das diferentes frações morfológicas. A calagem e a fosfatagem na dose de 141 mg dm -3 de P 2 O 5 incrementaram o crescimento e a produção do capimMarandu, devendo ser práticas indispensáveis ao cultivo desta forrageira em Latossolo Amarelo do Cerrado piauiense, Brasil. A aplicação de formononetina promoveu aumento da taxa de alongamento do colmo, número total de perfilho, massa seca de colmo verde e diminuiu a...

Biochemical and biological properties of soil from murundus wetlands converted into agricultural systems. Rev Bras Cienc Solo. 2019;43:e0180183.

Pastures are important food sources for Brazilian cattle herds. However, inadequate management of soil fertility has emerged as a major cause of low yield rates and of progressive degradation of these areas. The objective of the present study was to evaluate growth, by means of morphogenetic and structural characteristics, and yield of Brachiaria brizantha Stapf. cv. Marandu as functions of the application of the mycorrhizae stimulant formononetin, associated with lime and phosphate application. The experimental design was completely randomised with four replications, and the treatments were arranged in a 2 x 2 x 5 factorial scheme, consisting of two liming treatments (with and without limestone), two formononetin treatments (with and without application) and five P 2 O 5 doses (0, 25, 50, 100 and 200 mg dm -3 ). Three shoot cuttings were carried out after a first standardisation cutting to evaluate the morphogenetic and structural characteristics as well as the dry matter yield of different morphological fractions. Liming and phosphate application at the dose of 141 mg dm -3 P 2 O 5 increased growth and yield of Marandu grass, and these practices are essential for the cultivation of this pasture grass in Yellow Latosol of the Cerrado region of Piauí, Brazil. The application of formononetin increased stem elongation rate, total number of tillers and green stem dry matter, and decreased dead dry matter of Marandu grass, which are effects that contribute to the improvement of pasture quality. Key words: Brachiaria brizantha. Mycorrhizae. Pastures. Soil acidity. ResumoAs pastagens constituem importante fonte alimentar para os rebanhos brasileiros, entretanto, o manejo inadequado da fertilidade dos solos têm-se destacado como uma das principais causas dos baixos índices produtivos e da progressiva degradação destas áreas. O objetivo do presente estudo foi avaliar o crescimento, através das características morfogênicas e estruturais, e a produção da Brachiaria brizantha Stapf. cv. Marandu em função da aplicação do estimulante de micorrização formononetina associado a calagem e a fosfatagem. O delineamento experimental adotado foi o inteiramente casualizado, com quatro repetições, sendo os tratamentos dispostos num esquema fatorial 2 x 2 x 5, constituídos por dois tratamentos de calagem (com e sem calcário), dois de formononetina (com e sem aplicação) e cinco doses de P 2 O 5 (0, 25, 50, 100 e 200 mg dm -3 ). Foram realizados três cortes da parte aérea, após um primeiro corte de uniformização, para realização das avaliações das características morfogênicas e estruturais, bem como a produção de massa seca das diferentes frações morfológicas. A calagem e a fosfatagem na dose de 141 mg dm -3 de P 2 O 5 incrementaram o crescimento e a produção do capimMarandu, devendo ser práticas indispensáveis ao cultivo desta forrageira em Latossolo Amarelo do Cerrado piauiense, Brasil. A aplicação de formononetina promoveu aumento da taxa de alongamento do colmo, número total de perfilho, massa seca de colmo verde e diminuiu a...

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Cowpea is a widely grown annual legume in the North and Northeast regions of Brazil. It is one of the main sources of protein and income for the populations of these regions. However, few studies have shown the nutritional requirements, and symptomatology of nutritional deficiencies of cowpea cultivars. In this context, the objective of this work was to evaluate the initial growth and symptomatology of macronutrient deficiencies in cowpea plants of the BR17-Gurguéia cultivar. A randomized complete experimental design with three replications was used, with seven treatments consisted of nutrient solutions containing no N, P, K, Ca, Mg, or S, and a nutrient solution containing all macro and micronutrients as control, using one plant per plot. Plant height, stem diameter, number of leaves, leaf area, root volume, and shoot and root dry weights were evaluated, and visual symptoms of nutritional deficiencies were described at 30 days after planting. Nitrogen, phosphorus, potassium, calcium, and magnesium were the most limiting nutrients for the vegetative growth and biomass production of cowpea up to 30 days of cultivation. The absence of these elements in the nutrient solution caused morphological changes and visual symptoms that are characteristic of the nutritional deficiency of these nutrients.