Living Mulch Management Spatially Localizes Nutrient Cycling in Organic Corn Production

Abstract

Kura clover (Trifolium ambiguum) is a perennial living mulch species that can be used in conjunction with zone tillage to reduce nitrogen pollution, maintain ground cover, and provide nitrogen to crops. In such systems, kura clover is maintained between crop rows by limiting tillage only to within-row areas. However, the effect of zone-tilled living mulches on soil quality and nutrient cycling in these distinct regions is relatively unexplored. We examined three pools of labile soil organic matter (SOM): microbial biomass, particulate organic matter (POM), and permanganate oxidizable carbon (POXC). Soil samples were collected from both within-row and between-row locations of a zone-tilled kura clover living mulch at three time points per year: before spring zone tillage, approximately ten days after spring zone tillage and corn (Zea mays) planting, and at corn harvest in 2015 and 2016. In 2016, POM and POXC decreased within rows relative to between-row regions after tillage, suggesting that zone till management stimulated decomposition of readily available SOM to effectively localize nutrient cycling in this region and slow mineralization between rows where living kura clover remained. This work shows that zone-tilled living mulches may be a promising avenue for enhancing the synchrony of nutrient mineralization specifically within crop rows, while maintaining year-round ground cover between rows.

Three years of cover crops management increased soil organic matter and labile carbon pools in a subtropical vegetable agroecosystem

“…Different labile C pools also offer complementary information on soil functions not limited to SOM accumulation. For example, POX‐C reportedly represents a biologically active pool that strongly correlates with the soil's nutrient cycling potential and aggregate stability while reflecting management practices promoting SOM accumulation (Fine et al., 2017; Ginakes et al., 2020; Ramírez et al., 2020). On the other hand, Cmin measures a pool of soil C that is easily degradable by microbes and correlates with microbial biomass and metabolism (Anderson & Domsch, 1978; W. J. Wang et al., 2003).…”

Extending Cover Crop Benefits with Zone Till Management in Northern Organic Summer Squash Production

“…Despite the greater biomass N and lower residue quality in RV and RC systems relative to OP in 2016, POXC responded only to sampling time with a slight decrease by the post-harvest sampling time relative to all other time points. This slow decrease over time may be attributed to general microbial activity and decomposition of preexisting labile C pools over the growing season, as has sometimes been observed previously [42,43].…”

“…Labile C was unaffected by cover crop system, soil region, and sampling time in 2015. This was surprising, as this readily available C pool is typically utilized for co-metabolizing in N mineralization [42], and the OP system in particular contributed a large volume of high-quality cover crop residue immediately after the pre-kill soil sampling time in crop rows. Therefore, we expected to observe a decrease in IR POXC after cover crop termination as cover crop residue mineralized, but this was not observed.…”

“…Therefore, we expected to observe a decrease in IR POXC after cover crop termination as cover crop residue mineralized, but this was not observed. While the sensitivity of POXC to cover cropping practices has mixed results in the literature [42][43][44], some have concluded that it better reflects practices and systems that build soil organic matter rather than nutrient turnover [45,46]. Soil inorganic N responded to cover crop termination in both soil regions and cover crop systems in 2015.…”

The reflection of principles and values in worldwide organic agricultural research viewed through a crop diversification lens. A bibliometric review

“…'Soil management' and 'Weed control' (topics 5 and 3) were also jointly addressed in some articles, for instance on the design of organic cropping systems with conservation tillage or no-tillage, in which synergies between reduced weed infestation and maintenance of long-term fertility of the system for productivity are sought (Peigné et al 2007;Halde et al 2015;Hashimi et al 2019;Littrell et al 2021). The proximity between these two topics was also reflected in the large number of alternative products tested to control weeds while acting assoil amendments, such as tea compost (Vail et al 2020), green manure (Carlesi et al 2020) and dead mulches (Sihi et al 2017;Ginakes et al 2020), and additional and novel crops in the rotations (e.g. quinoa) (Wieme et al 2020).…”