Single farming systems (SFS) such as monocultures may negatively affect soil structural quality. This study tested the hypothesis that integrated farming systems (IFS), i.e., the combination of cropping and forestry and/or livestock farming, improves soil structural quality, root development and soil organic carbon. An experimental area was set up in 2012 at the Canguiri experimental farm belonging to the Federal University of Paraná, Southern Brazil. The soils are predominantly Ferralsols. The experimental treatments representing different farming systems, organized in a random block design with three replicates, were: Forestry (F), Conventional Crop Production (C), Livestock (L), and integrated Crop-Forestry (CF), Crop-Livestock (CL), Livestock-Forestry (LF), and Crop-Livestock-Forestry (CLF). In situ measurements and sampling were carried out in the 0–0.3 m layer during summer 2019/20, and included soil penetration resistance (PR), soil structural quality based on visual evaluation of soil structure (SqVESS scores), root length (RL), root volume (RV) and soil organic carbon content (SOC). Soil structural quality, penetration resistance, root length and volume, and SOC varied between farming systems, but no significant differences were found between single (C, L, F) and integrated farming systems (CF, CL, LF, CLF). The single system Forestry (F) and the integrated systems including forestry (LF, CF, CLF) tended to have higher SqVESS scores, i.e. poorer soil structural quality, and higher PR, which we associate with the generally drier soil conditions that are due to higher soil water uptake and higher interception and reduce the frequency of wetting-drying cycles. Roots were concentrated in the shallow soil layer (0–0.1 m depth), and this was especially pronounced in the Crop (C) single farming system. Based on the measured values, our results suggest an acceptable soil structural quality in all farming systems. Our data revealed strong, significant relationships between soil structural quality, penetration resistance, root growth and SOC, demonstrating that improvements in soil structure results in lower soil penetration resistance, higher root volumes and higher SOC, and vice versa. Soil PR was positively correlated with SqVESS (R2 = 0.84), indicating that better soil structural quality resulted in lower soil mechanical resistance. This, in turn, increased root length and volume, which increases carbon input to soil and therefore increases SOC in the long run.

Lima bean (Phaseolus lunatus L.) is a crop with great economic and social importance for the Brazilian Northeast. The water crisis in recent years has affected crop production, especially in the semi-arid region. Thus, the use of lower quality waters (saline) becomes a necessary alternative, but it can affect the growth and yield of agricultural crops. The objective of this study was to evaluate the effect of salt stress on the initial growth and biomass accumulation of four lima bean cultivars. The experiment was carried out in a protected environment in a completely randomized experimental design in a 5 x 4 factorial scheme, with four replicates. The treatments consisted of 5 salinity levels in irrigation water with electrical conductivity (ECw) of 1.0, 2.0, 3.0, 4.0 and 5.0 dS m -1 and four cultivars: Branquinha (C1), Manteiguinha (C2), Espírito Santo (C3) and Orelha-de-vó (C4). The variables analyzed were plant height, number of leaves, leaf area, stem diameter, root length, shoot dry mass, root dry mass and total dry mass. At the end of the experiment, electrical conductivity of the soil saturation extract was evaluated. The cultivar Manteiguinha was more tolerant to salinity than the others, considering the variables number of leaves and plant height. However, it was not possible to identify variations in the tolerance of the four lima bean cultivars based on biomass production, indicating the need for further studies that can prove the existence of genetic variability in relation to the effects of salt stress on this species