Crop rotation and inoculation increase soil bradyrhizobia population, soybean grain yields, and profitability.

Crop rotation and rhizobial inoculation are strategies to increase yield by means of organic matter addition and modulation of microbial diversity. However, the extent to which these agricultural practices change soil Bradyrhizobium populations, soybean grain yield, and economic benefits to farmers is unclear. Thus, this study aimed to evaluate the interaction between crop rotation and inoculation of soybean (Glycine max) cultivated in two contrasting soils (clayey and sandy soil) on biological nitrogen fixation components, grain yields, and profits. Field experiments with a three-year crop rotation system were carried out to compare effects of inoculation and crop rotations on soil chemical attributes, bradyrhizobia most probable number (MPN) and diversity, soybean nodulation, grain yield, and economic indicators of inoculation in different crop rotations. The crop rotation did not affect the soil MPN cells of bradyrhizobia, but the inoculation and the soil sampling time did, ranging from 3.61-4.42 to 4.40-4.82 in the sandy soil, while in the clayey soil they were from 5.19-6.34 to 6.61-7.14 in Log10 per g of soil with higher population after harvest of summer crops. In the clayey soil, crop rotation influenced soybean nodulation. The grain yield of inoculated soybean in the clayey soil was higher than that in the sandy soil. Soybean inoculation with Bradyrhizobium spp. increased the profitability of agricultural production systems by up to 45% in clayey soil and up to 7% in sandy soil.

The diversification of species in crop rotation increases the profitability of grain production systems.

Crop rotation with species diversification contributes to the control of pests, diseases and weeds and improves soil fertility and conservation, which can lead to increased profitability in grain production systems. The objectives of this study were to determine whether grain production systems that employ crop rotation with species diversification are more productive and profitable than double-cropping rotations without diversification and to analyze the revenues and production costs of these cropping systems. An experiment was conducted in a region with subtropical climate between the crop years of 2014-2015 and 2019-2020. The experiment consisted of a randomized block design with six treatments and four replicates. The treatments consisted of six grain production systems, including five rotations with varied levels of species diversification and a corn-soybean rotation without species diversification, all under no-tillage. Productivity, revenue, production cost and profit indicators were analyzed. Productivity was compared by Duncan's test (p ≤ 0.05). The grain production systems with species diversification showed better productivity and profitability than the corn-soybean system. The profit of the systems with species diversification was on average 37% higher than that of the system with corn-soybean rotation. In summary, grain production systems that employ crop rotation with species diversification showed higher productivity and profitability than the corn-soybean rotation without species diversification.

Production and profitability of diversified agricultural systems.

Diversified crop rotation is an option for expanding producer incomes, and its adoption has presented a series of agronomic advantages compared to less diversified crop rotation systems. In this context, the objective of this study was to verify if higher-diversified crop rotation systems perform economically better than low-diversified ones. To this end, we conducted an experiment in no-tillage crop areas in Londrina, in south of Brazil, for the years 2014/15 to 2016/17. The experiment design was randomized blocks, with six treatments, consisting of crop rotation systems with different levels of diversification, and four replications. We observed that higher-diversified crop rotation systems yield higher revenues and profits. Only these systems, specifically the ones that included canola-corn, crambe-corn, and safflower-soybeans, or wheat-corn+brachiaria, canola-corn, and edible beans-soybeans were economically feasible. Despite higher cost, diversified systems with a greater number of commercial crops in winter presented higher profits. However, diversified systems with a high proportion of cover crops in winter are economically infeasible because their net return is negative.

Economic profitability of crop rotation systems in the Caiuá sandstone area / Rentabilidade econômica de sistemas de rotação de culturas em área de arenito Caiuá

ABSTRACT: Even in areas of predominance of Caiuá sandstone, with soils of low natural fertility that are highly susceptible to erosion and degradation processes, farmers have adopted systems with little diversification, because they believe that they provide a greater economic return. However, agricultural practices such as crop rotation can bring agronomic benefits in terms of conservation agriculture, in addition to economic gains, circumventing edaphoclimatic difficulties in the region. In this context, the objective of this study is to verify whether no-till crop rotation systems are economically profitable, in a Caiuá sandstone area in the northwest region of the Brazilian state of Paraná. To this end, an experiment was conducted in the municipality of Umuarama, state of Paraná, in the crop year 2014/15 to 2016/17. The experimental design used random blocks, with four treatments and four repetitions. The treatments consisted of four crop rotation systems, involving wheat, black oats, canola, safflower, rye, crambe, beans, maize, fodder radish, soybean, sorghum, lupin beans, buckwheat, and triticale cultivars. Crop yields, operating costs, income, and net farm income were assessed. From the results, it was reported that the highest income was obtained in the systems that adopted the largest number of winter and summer commercial crops. Only one treatment was profitable, that is, it had a positive net farm income. This scenario may be associated with the fragility of the region's soil, which having low fertility, requires a high investment in fertilization and liming to ensure adequate production.

RESUMO: Mesmo em áreas de predomínio do arenito Caiuá, com solos de baixa fertilidade natural e altamente susceptíveis a processos de erosão e degradação, agricultores têm adotado sistemas com baixa diversificação, por acreditarem que estes apresentam maior retorno econômico. No entanto, práticas agrícolas como a rotação de culturas podem trazer benefícios agronômicos, relativos à agricultura conservacionista, além de ganhos econômicos, contornando dificuldades edafoclimáticas da região. Neste contexto, o objetivo deste estudo foi verificar se na região Noroeste do Paraná, em área de arenito Caiuá, sistemas de rotação de culturas sob plantio direto apresentam rentabilidade econômica. Para tanto, foi conduzido um experimento no município de Umuarama, estado do Paraná, entre anos agrícolas de 2014/15 a 2016/17. O delineamento experimental foi de blocos ao acaso, com quatro tratamentos e quatro repetições. Os tratamentos constituíram-se de quatro sistemas de rotações de culturas, que envolveram cultivares de trigo, aveia preta, canola, cártamo, centeio, crambe, feijão, milho, nabo forrageiro, soja, sorgo, tremoço, trigo mourisco e triticale. Foram avaliadas as produtividades das culturas, os custos variáveis, as receitas e as margens brutas. A partir dos resultados, verificou-se que as melhores receitas foram obtidas nos sistemas que adotaram o maior número de culturas comerciais de inverno e verão. Somente um tratamento apresentou rentabilidade, ou seja, margem bruta positiva. Este cenário pode estar associado à fragilidade do solo da região, que por serem de baixa fertilidade, demandam alto investimento com adubação e calagem, para garantir uma produção adequada.

The dynamics of coffee production in Brazil.

Coffee is a crop of significant importance for Brazilian agrobusiness. There is evidence that both the geographic distribution of coffee production, and the varieties of coffee produced, have changed throughout Brazil over the course of time. Furthermore, it appears that these developments are associated with structural changes resulting from reductions in government intervention and its effects on prices in the coffee market, which has established a new dynamic of coffee production in the country. In this context, this study's objective is to analyze the dynamics of coffee production in Brazil, to identify the Brazilian micro-regions specializing in coffee activities, and to track how the spatial distribution of these micro-regions has varied over time. In so doing, the study aims to identify defining economic characteristics of primary coffee-producing regions. Drawing primarily on data from the Brazilian Institute of Geography and Statistics, the study proceeds by applying Pearson correlation, Granger causality test, location quotient, principal components, and clustering analyses to explore how, during the 1984-2015 period, significant changes occurred in the distribution of regions specializing in coffee production. States such as Paraná and São Paulo, historically important coffee producers, declined in importance, leaving only a few micro-regions in these states specialized in coffee production. During the 2014/15 biennium, 80% of the coffee-specialized micro-regions were concentrated in the states of Minas Gerais, Bahia, Rondônia, and Espírito Santo. Minas Gerais and Bahia primarily produced arabica coffee, while Rondônia specialized in conilon (robusta) coffee. Overall, coffee produced in Brazil improved in quality and value-added over this period.