Fabrício Tomaz Ramos

Este estudo teve como objetivo avaliar o efeito da compactação do solo e da adubação com dejetos líquidos de suínos (DLS) sobre as características produtivas e morfológicas do capim Urochloa brizantha cv. BRS Paiaguás. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 3 × 4, com três níveis de densidade do solo (NDS: 1,0; 1,2; 1,3 g cm-3) e quatro doses de DLS (0; 100; 200; 300 m³ ha⁻¹), totalizando 36 unidades experimentais em colunas de PVC (35 cm de altura e 200 mm de diâmetro). Após 15 dias da semeadura, as plantas foram submetidas a corte de uniformização e, aos 40 dias, foram avaliados o número de folhas, o número de perfilhos, a altura da planta, o diâmetro do colmo, a massa seca da parte aérea e a massa seca das raízes. Os resultados indicaram que o maior NDS (1,3 g cm-3) favoreceu o desenvolvimento morfológico da planta, enquanto doses intermediárias de DLS (164 a 294 m³ ha⁻¹) promoveram os maiores incrementos na biomassa aérea e radicular. O capim-paiaguás demonstra elevado desenvolvimento radicular mesmo em solo mais compactado, evidenciando potencial para cultivo em condições de restrição física. A aplicação de dejeto líquido de suínos influencia positivamente as características morfológicas da forrageira e contrubui para a melhoria das propriedades físicas do solo. Palavras-chave: adubação orgânica; características morfológicas; densidade do solo; Urochloa brizantha.

Family farming is a cornerstone of Brazil's economic and social structure. It accounts for a significant portion of the national food production and plays a crucial role in promoting food security in the country. In the Metropolitan Region of the Cuiabá River Valley and Surroundings, this segment encompasses approximately 28,000 families residing in rural areas, organized into 10,547 agricultural establishments. The strengthening of family farming depends on its support by public policies which are capable of understanding regional specificities and creating effective mechanisms for the development and consolidation of the sector. In this context, a partnership was established between the Mato Grosso Company of Rural Research, Assistance, and Extension (EMPAER) and Embrapa, to develop a digital platform that integrates data across different territorial dimensions, aiming to characterize the region and, above all, provide analytical tools to support public policy and local investment decisions. This solution was based on the strategic territorial intelligence concept, which thematically organizes spatial data into five major frameworks: natural, agrarian, agricultural, infrastructural, and socioeconomic. We expect the platform to support territorial management efforts by public and private organizations by classifying the region’s municipalities according to their environmental and production potential. This, in turn, will assist research institutions and organizations responsible for rural planning, management, and technical assistance.

A agricultura familiar representa um pilar fundamental da estrutura econômica e social do Brasil, sendo responsável por uma parte significativa da produção nacional de alimentos e desempenhando um papel crucial na promoção da segurança alimentar no País. Na Região Metropolitana do Vale do Rio Cuiabá e Entorno, este segmento é representado por cerca de 28.000 famílias residentes no meio rural, organizadas em 10.547 estabelecimentos agropecuários. Seu fortalecimento depende do apoio de políticas públicas capazes de compreender especificidades regionais e criar mecanismos eficientes de desenvolvimento e consolidação do setor. Neste contexto, a Empresa Mato-Grossense de Pesquisa, Assistência e Extensão Rural (EMPAER) e a Embrapa estabeleceram uma parceria para desenvolver uma plataforma digital capaz de integrar dados de diversas dimensões territoriais. O objetivo foi caracterizar a região de forma abrangente e, principalmente, disponibilizar ferramentas de análise inteligente que auxiliem na formulação de políticas públicas e na orientação de investimentos locais. A solução foi estruturada a partir do conceito de inteligência territorial estratégica, que prevê a organização temática de dados espaciais em cinco grandes quadros: natural, agrário, agrícola, de infraestrutura e socioeconômico. Espera-se que a plataforma possa ser utilizada para subsidiar ações de gestão territorial de organizações públicas e privadas por meio da tipificação dos municípios da região em função dos seus potenciais ambientais e produtivos, apoiando instituições de pesquisa, órgãos de planejamento, gestão e de assistência técnica rural.

Os solos brasileiros, no geral, são muito intemperizados devido ao clima predominantemente tropical, resultando em elevada acidez, baixa saturação de bases e teores de fósforo limitantes. Sabe-se que a calagem e a fosfatagem melhoram as condições químicas do solo e a produtividade de forragem, mas se aplicados juntos no preparo do solo, a disponibilidade do fósforo às plantas tende a reduzir, sobretudo, fosfatos de maior solubilidade. Diante disso, como teores adequados de fósforo são essenciais no desenvolvimento inicial das raízes, objetivou-se avaliar o resultado da aplicação simultânea e espaçada no tempo do fosfato natural reativo de Bayovar de baixa solubilidade com a calagem, comparado ao fosfato monoamônico de maior solubilidade na produção do capim BRS Zuri. Verificou-se que a combinação dos fosfatos com calcário não apenas aumentou a altura das plantas e a matéria orgânica no primeiro ano como, também aumentou significativamente a produtividades de matéria verde e seca e de fibra em detergente ácido. A diferença é que o efeito do Bayovar é mais pronunciado no segundo ano, evidenciando sua importância como adubação de manutenção do capim BRS Zuri, comparado ao fosfato monoamônico que teve maior efeito no primeiro ano, destacando sua influência no arranque inicial. Portanto, recomenda-se a combinação de fontes de fosfatos com disponibilidade diferenciada, visando melhorar a qualidade química do solo para atingir maiores produtividades do capim BRS Zuri.

In 2014, the Upper Paraguay River Basin (UPB) plateau in Brazil maintained only 39.5% of its native vegetation cover, most of which was located in riparian zones that were generally degraded, in legal reserve areas, or in regions without agricultural potential. Due to the lack of practical results in the region, so that farmers could base their projects for the recovery of degraded areas, this work was designed to determine the long-term result of three revegetation techniques and their contributions to soil attributes and vegetative parameters, in the riparian zone of a watershed in the municipality of Campo Verde, located in the UPB. It was found that in only seven years, the technique of distributing a mixture of seeds rich in nitrogen-fixing plant species with washed sand and composted cotton tow, followed by incorporation with light harrowing, favored a rapid establishment of native plants. In this case, the number of species and the floristic diversity was the closest to those of the Tropical Cerrado, i.e., the control. In this technique, Brachiaria brizantha was not dominant , and the mean of total organic carbon storage in the soil (TOCS) was significantly lower, thereby indicating that riparian zones with higher TOCS do not necessarily have greater plant diversity. Therefore, the competition caused by B. brizantha can affect ecological diversity in areas undergoing ecological succession.

Mato Grosso, with a total area of 903357 km², does not have an official methodology for estimating soil potential acidity (H + Al), and determination of H + Al using the standard method is onerous and time consuming. The objective of this study was to compare estimated values of H + Al determined using the standard calcium acetate method with those obtained using three buffer methods, namely, the Shoemaker, McLean, and Pratt (SMP) buffer, Sikora buffer, and Santa Maria buffer (SMB) methods, with samples of the main classes of cultivated soils in the state of Mato Grosso. A total of 196 soil samples were collected from the arable layer (0-20 cm) in agropastoral and adjacent native systems. Statistical models were obtained and compared with models used by laboratories that are hypothetically inadequate because there is no calibration for soils in the state. After laboratory analyses, the paired H + Al and equilibrium pH values corresponding to the equilibrium of each buffer solution (SMP buffer, SMB, and Sikora buffer) were subjected to nonlinear regression analysis (P < 0.05). The SMB method, which does not release pollutant residues into the environment, was better than the Sikora and SMP methods for replacing the standard method used in state laboratories for soil analysis, that is, H + Al (cm3 c dm-3) = 51.189 -25.70 ln(pHSMB) (R2 = 0.88, P < 0.0001). Thus, if laboratories use uncalibrated equations to estimate soil potential acidity, the recommended limestone correction will be underestimated or overestimated, which may compromise crop productivity in Mato Grosso.

BACKGROUND: Agricultural conservation practices increase total organic carbon storage in soil (T_OCS), a factor that is correlated with the physical and chemical qualities of highly weathered soils. In this study, we investigated the effects of T_OCS on the physicochemical attributes of a Latosol after 10 years of no‐till management in Mato Grosso State, Brazil.RESULTS: T_COS was highly correlated (r = 0.92) with cation exchange capacity (CEC, pH = 7) and soil density. In the top 0.2 m soil layer, CEC increased by 25% with every 1.8 kg m⁻² of stored organic carbon. Eliminating soil organic matter reduced CEC from an already low value of 8.40 cmol_c kg⁻¹ to 4.82 cmol_c kg⁻¹. Humus is therefore clearly important for the formation of a negative liquid charge in a predominantly electropositive but clayey soil.CONCLUSION: We confirmed that T_OCS is an indicator related to the physiochemical characteristics of weathered soils. Furthermore, our results demonstrate that the increased carbon storage under non‐tilling systems is essential for guaranteeing weathered soil fertility in tropical climates. © 2018 Society of Chemical Industry

Demarcating soil management zones can be useful, for instance, delimiting homogeneous areas and selecting attributes that are generally correlated with plant productivity, but doing so involves several different steps. The objective of this study was to identify the chemical and physical attributes of soil and soybean plants that explain crop productivity, in addition to suggesting and testing a methodological procedure for defining soil management zones. The procedure consisted of six steps: sample collection, data filtering, variable selection, interpolation, grouping, and evaluation of management zones. The samples were collected in an experimental area of 12.5 ha cultivated with soybean during the 2013/14 crop in Dystrophic Red Latosol, in Mato Grosso, Brazil. A total of 117 pairs of plant and soil samples were collected. Student’s t-test was used (α = 0.02) to verify that the number of samples was adequate for correlation analysis. Results showed that only the P and Mn content in the grains explained (based on R2 values) the variation in soybean grain productivity the area. Based on the interpolation of these contents by ordinary kriging, the fuzzy C-means algorithm was used to separate them into groups by similarity. Division into two groups was the best option, which could be differentiated by Mann-Whitney test (P < 0.05), resulting in a map with 10 management zones.

The no-tillage technique has been expanding in the Brazilian Cerrado (savanna), but due to the rapid decomposition of residues and few options for profitable rotation crops, soil compaction can be a problem, seriously reducing water availability to plants. Determination of the least limiting water range (LLWR) is a sensitive method to assess the current soil compaction state, although it is operationally and economically beyond the reach of most farmers. Therefore, the aim of this study was to determine the LLWR of a highly loamy typic Oxisol (dystrophic red Latosol) and to evaluate the possibility of estimating it by using the relative bulk density (RBD), determined based on the soil compaction curve, which in comparison is a relatively fast and inexpensive method. The results showed that RBD was strongly correlated with LLWR, with coefficient of determination between 0.69 and 0.95, besides having low mean standard estimation error of at most 0.016 m3 m-3 (P < 0.0001), making measurement of the RBD satisfactory, to estimate the LLWR. Besides this, the RBD values corresponding to BDcritical, that is, when LLWR = 0, were very near the RBD value (≈ 0.90), taken as the upper limit of physical quality for adequate plant growth. Therefore, because of the high cost and laboratory time necessary to determine the LLWR for each type of soil, a viable alternative is to use the reference value or maximum acceptable RBD limit value of 0.90 for management of soil compaction, obtained through geostatistical analyses, to ascertain the variability in the cultivated areas where RBD ≥ 0.90. In short, it is technically and economically feasible to estimate the LLWR based on the RBD. Key words: Soil compaction curve, proctor normal test without sample reuse, no-till farming in Mato Grosso, Midwest region of Brazil.

Soil carbon (C) stock determination can subsidize discussions on the continuity of an agricultural management. This study aimed to evaluate the stocks of total organic C (S_TOC) and labile C (S_LC), and the indices of C lability (CLI), C compartment (CCI) and C management (CMI), and correlate them with chemical and physical attributes of a Red Yellow Latosol (Oxisol) managed for 38 years with different tillage systems in a Cerrado region of Mato Grosso, Brazil. Disturbed and undisturbed soil samples were collected in three layers (0-0.05, 0.05-0.10 and 0.10-0.20 m). The CMI (CLI x CCI) showed higher S_TOC possibly as the tillage depth decreased, because none of the tillage systems conserved S_TOC and S_LC in the layers of 0-0.05 and 0.05-0.10 m, compared with the Native Cerrado, i.e., soil C conservation only occurred in the layer of 0.10-0.20 m. Although the percentage of S_LC in S_TOC was lower, only S_LC was correlated with soil chemical and physical attributes and, based on the multiple linear regression analysis, S_LC was explained in 54% (R²) by the cation exchange capacity and soil micropores. Therefore, for monitoring purposes, the S_LCestimated can be useful to evaluate soil C storage.