Declining biodiversity (BD) is aecting food security, agricultural sustainability, and environmental quality. Agroforestry (AF) is recognized as a possible partial solution for BD conservation and improvement. This manuscript uses published peer-reviewed manuscripts, reviews, meta-analysis, and federal and state agency documents to evaluate relationships between AF and BD and how AF can be used to conserve BD. The review revealed that floral, faunal, and soil microbial diversity were significantly greater in AF as compared to monocropping, adjacent crop lands, and within crop alleys and some forests. Among the soil organisms, arbuscular mycorrhizae fungi (AMF), bacteria, and enzyme activities were significantly greater in AF than crop and livestock practices. Agroforestry also creates spatially concentrated high-density BD near trees due to favorable soil-plant-water-microclimate conditions. The greater BD was attributed to heterogeneous vegetation, organic carbon, microclimate, soil conditions, and spatial distribution of trees. Dierences in BD between AF and other management types diminished with time. Evenly distributed leaves, litter, roots, dead/live biological material, and microclimate improve soil and microclimate in adjacent crop and pasture areas as the system matures. Results of the study prove that integration of AF can improve BD in agricultural lands. Selection of site suitable tree/shrub/grass-crop combinations can be used to help address soil nutrient deficiencies or environmental conditions. Future studies with standardized management protocols may be needed for all regions to further strengthen these findings and to develop AF establishment criteria for BD conservation and agricultural sustainability.

Cover crops (CC) improve soil quality, including soil microbial enzymatic activities and soil chemical parameters. Scientific studies conducted in research centers have shown positive effects of CC on soil enzymatic activities; however, studies conducted in farmer fields are lacking in the literature. The objective of this study was to quantify CC effects on soil microbial enzymatic activities (β-glucosidase, β-glucosaminidase, fluorescein diacetate hydrolase, and dehydrogenase) under a corn (Zea mays L.)–soybean (Glycine max (L.) Merr.) rotation. The study was conducted in 2016 and 2018 in Chariton County, Missouri, where CC were first established in 2012. All tested soil enzyme levels were significantly different between 2016 and 2018, irrespective of CC and no cover crop (NCC) treatments. In CC treatment, β-glucosaminidase activity was significantly greater at 0–10 cm depth in 2016 and at 10–20 and 20–30 cm in 2018. In contrast, dehydrogenase activity was significantly greater in NCC in 2018. Soil pH and organic matter (OM) content were found to be significantly greater in CC. Overall, CC have mixed effects on soil enzyme activities and positive effects on soil OM compared to NCC. This study highlights the short-term influence of CC and illustrates the high spatial and temporal variability of soil enzymes under farmer-managed fields.

Crop production is reduced by insufficient and/or excess soil water, which can significantly decrease plant growth and development. Therefore, conservation management practices such as cover crops (CCs) are used to optimize soil water dynamics, since CCs can conserve soil water. The objective of this study was to determine the effects of CCs on soil water dynamics on a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] rotation at three soil depths over 3 yr. The study was conducted at the Chariton County Cover Crop Soil Health Research and Demonstration Farm (CCSH) in Missouri. Initial CC establishment occurred in 2012. Volumetric soil water content (VWC) was monitored at 15‐min intervals with calibrated Waterscout SM100 soil moisture sensors (Spectrum Technologies) at three depths (10, 20, and 30 cm) in 2016, 2017, and 2018. Cover crop soils maintained numerically higher VWC values compared with no CC (NCC) at both 10‐ and 20‐cm depths throughout the study period where the differences were significant in some weeks. The subsurface soil water recharge was greater in CC soils at both 10‐ and 20‐cm depths compared with NCC in March 2017. The results imply that CC soils have maintained higher VWC levels during vegetative period of the CC growth where the differences were significant in some weeks compared with NCC at all three soil depths. These findings can be used to promote CC adoption for better soil water storage and develop CC management plans for corn–soybean rotations on claypan soils.