Given the hypothesis that co-inoculation with plant growth-promoting bacteria (PGPB) enhances the beneficial effects of Rhizobium tropici with greater mineral nutrition, optimizes biological nitrogen fixation and reduces use of fertilizers in bean plants, the objective of this research was to evaluate the synergistic effects of Rhizobium tropici associated with Azospirillum brasilense, Bacillus subtilis, Pseudomonas fluorescens and their combinations, on increasing the efficiency of NPK fertilization to obtain high winter yields of the (irrigated) common bean in the Cerrado region. The experiment was carried out in the field over two years in a Rhodic Hapludox under a no-till system in Selvíria, Brazil. The experimental design comprised complete randomized blocks with four replications in a 3 × 7 factorial scheme. The treatments consisted of three doses of NPK fertilizer (control—0 kg ha⁻¹ (control); 50% of the recommended dose; 100% of the recommended dose in two parts) and seven doses of inoculation or co-inoculation (control; Rhizobium tropici; R. tropici + Azospirillum brasilense; R. tropici + Bacillus subtilis; R. tropici + Pseudomonas fluorescens; R. tropici + A. brasilense + B. subtilis; R. tropici + A. brasilense + P. fluorescens). The PGPB in the co-inoculations increased the hundred-grain weight, the grain pod⁻¹, the grain plant⁻¹ and the grain yield following the NPK doses. The grain yield of the common bean was increased by co-inoculation with R. tropici + A. brasilense + P. fluorescens without NPK treatments, co-inoculation with R. tropici + P. fluorescens and R. tropici + A. brasilense + B. subtilis with the 50% dose of NPK and co-inoculation with R. tropici + B. subtilis with the recommended dose of NPK fertilizer (100%).

Core Ideas: (1) Superficial soil compaction in a no-tillage system. (2) Cultivation of cover crops in succession with annual crops. (3) Soil decompression with cultivation of the predecessor soil cover. (4) Unpacking soil with mechanical chiseling. (5) Biological chiseling with the cover crop effect on the common bean yield. Mechanical soil intervention with a chisel in cover crops (CC) is a promising alternative strategy to minimize superficial compaction of soil in a no-tillage system (NTS) of the Brazilian Cerrado. Thus, the objective of the current study was to evaluate the effects of mechanical chiseling associated with successor and predecessor cover crops on agronomic components and the grain yield of the common bean in NTS for two consecutive years. The experiment was designed in randomized blocks in a 5 × 2 factorial scheme with four replications. The treatments consisted of five cover crops (Cajanus cajan, Crotalaria juncea, Urochloa ruziziensis and Pennisetum glaucum and fallow), associated or not with soil mechanical chiseling. The results indicated that cultivation of C. juncea and U. ruziziensis as cover crops increased the initial and the final plant population and the number of pods plant⁻¹ of the common bean. The cultivation of P. glaucum as a predecessor crop with chiseling was observed with greater shoot dry matter and a greater number of grains pod⁻¹ and plant⁻¹ of the common bean while C. cajan and C. juncea have increased leaf N content in the common bean. The predecessor crops of C. juncea and P. glaucum with chiseling increased the grain yield of the “winter” common bean in succession. Therefore, cultivation of C. juncea and P. glaucum as predecessor crops along with chiseling are considered a sustainable strategy for improving the growth and the yield of successive crops in a no-tillage system of the Brazilian Cerrado.

This research analyzed the effects of inoculation with Rhizobium tropici, combined with beneficial microorganisms, on the reduction of NPK fertilization and its impacts on common beans. Conducted in two types of soil (clayey Oxisol and sandy Ultisol), the experimental design was a randomized block design under a factorial scheme 4 × 4, with different combinations of inoculation (Rhizobium tropici alone or in combination with Azospirillum brasilense, Bacillus subtilis, and Trichoderma harzianum) and fertilization doses (0%, 33%, 66%, and 100% of the recommended dose). The results showed that inoculation with R. tropici, especially in combination with Trichoderma harzianum, increased nodule formation and improved agronomic parameters such as leaf chlorophyll, dry matter of the plant, number of pods, and grains. Co-inoculation with Azospirillum brasilense resulted in a significant increase in grain yield, particularly in clayey soil with 33% NPK. Inoculation with lower doses of NPK was sufficient for good yield, suggesting the feasibility of reducing the use of mineral fertilizers. This study indicates that soils with corrected fertility, in a no-tillage system, can contribute to the reduction of fertilizer use due to the cycling of organic matter and improvement of soil health. Additionally, the use of microorganisms is an effective ally for the sustainability of agroecosystems.

Mechanical soil intervention with a chisel in cover crops (CCs) is a promising strategy for minimizing the superficial compaction of soil in a no-tillage system (NTS). The objective of this study was to evaluate the effect of mechanical chiseling associated with successive crops and preceding cover crops to assess grain yield and changes in soil chemical properties after rice cultivation for two consecutive years. The experimental design comprised randomized blocks in a 5 × 2 factorial scheme with four replications. The treatments consisted of five cover crops (Cajanus cajan, Crotalaria juncea, Urochloa ruziziensis, Pennisetum glaucum, and fallow), with or without soil mechanical chiseling. Soil samples from the 0–5, 5–10, 10–20, and 20–40 cm layers were collected, and the chemical properties were analyzed after rice cultivation. Under U. ruziziensis, the chemical properties were improved by mechanical scarification; however, the initial acidity increased in the 5–40 cm layer. The cultivation of P. glaucum and C. juncea prior to rice, regardless of scarification, improved the soil chemical properties in the 0–40 cm layer. Mechanical soil scarification and the use of C. cajan as a cover crop increased the grain yield of upland rice by approximately 552 and 1454 and 1330 kg ha⁻¹ compared to the P. glaucum and U. ruziziensis, respectively.

DESEMPENHO AGRONÔMICO DE CULTIVARES DE LÚPULOS EM CLIMA TROPICAL NA NOVA ALTA PAULISTA LUIZ GUILHERME VICINO VIDAL1, PAULO RENATO MATOS LOPES1, MARCELA PAGOTI BERGAMINI-LOPES1, VAGNER DO NASCIMENTO1, SAMUEL FERRARI1 1 Departamento de Produção Vegetal, Faculdade de Ciências Agrárias e Tecnológicas, Universidade Estadual Paulista – FCAT/Unesp. Rodovia Comandante João Ribeiro de Barros, km 651, Bairro das Antas, CEP 17915-899. Dracena, São Paulo, Brasil. E-mail: lgvv@hotmail.com.br; prm.lopes@unesp.br; marcela.pagoto@gmail.com; vagner.nascimento@unesp.br; samuel.ferrari@unesp.br RESUMO: Esta pesquisa visou avaliar o desenvolvimento agronômico inicial de cultivares de lúpulo na região da Nova Alta Paulista em função a aplicação de fertilizante após o plantio. O delineamento experimental inteiramente casualizado foi realizado com seis repetições em esquema fatorial 2 x 3, correspondente a dois cultivares de lúpulo (Hallertau e Cascade) e a três dosagens do formulado 20-05-20 (300, 600 e 900 kg ha-1), aplicadas 60 dias após o plantio das mudas. O período de desenvolvimento vegetal ocorreu entre novembro de 2018 e a colheita, que ocorreu durante o mês de junho de 2019, sendo avaliado: altura das plantas; teor foliar de N, P e K; biomassa seca da parte aérea; e peso de cones por planta. Após 8 meses de cultivo, ambas as variedades de lúpulo mostraram desempenho similar. Doses acima de 300 kg ha-1 do fertilizante resultaram em menor desenvolvimento, especialmente na variedade Cascade. Os cultivares lúpulos cultivados em clima tropical priorizaram a absorção de nitrogênio, seguido de potássio e fósforo. Embora a produtividade tenha sido modesta no primeiro ano, evidencia-se o potencial agronômico e econômico do lúpulo no Brasil, abrindo caminho para sua exploração em regiões como a Nova Alta Paulista. Palavras-chaves: cascade, fertilizante, hallertau, Humulus lupulus. AGRONOMIC PERFORMANCE OF HOP CULTIVARS IN TROPICAL CLIMATE IN NOVA ALTA PAULISTA This research aimed to evaluate the initial agronomic development of hop cultivars in the Nova Alta Paulista region on the basis of fertilizer application after planting. The completely randomized experimental design was performed with six replications in a 2 × 3 factorial scheme, corresponding to two hop cultivars (Hallertau and Cascade) and three doses of 20-05--20 fertilizer (300, 600, and 900 kg ha -1) applied 60 days after transplanting. The vegetative development period occurred between November 2018 and June 2019, with evaluations of plant height; leaf nitrogen, phosphorus, and potassium contents; aboveground biomass; and cone weight per plant. After 8 months of cultivation, both hop varieties presented similar performance. Fertilizer doses above 300 kg ha -1 resulted in reduced development, especially in the Cascade cultivar. N absorption is prioritized in hops cultivated in tropical climates, followed by potassium and phosphorus absorption. Despite the modest yield in the first year, the agronomic and economic potential of hops in Brazil is evident, paving the way for their exploration in regions such as Nova Alta Paulista. Keywords: cascade, fertilizer, hallertau, Humulus lupulus.