Nutrient Management with Cover Crops and Compost Affects Development and Yield in Organically Managed Sweetpotato Systems

Abstract

<jats:p>A 3-year field experiment was initiated in 2001 to evaluate different organic sweetpotato production systems that varied in cover crop management and tillage. Three organic systems: 1) compost and no cover crop with tillage (Org-NCC); 2) compost and a cover crop mixture of hairy vetch and rye incorporated before transplanting (Org-CCI); and 3) compost and the same cover crop mixture with reduced tillage (Org-RT) were compared with a conventionally managed system (Conv) with tillage and chemical controls. Yield of No. 1 sweetpotato roots and total yield were similar among management systems each year, except for a reduction in yield in Org-RT in 2002. The percentage of No. 1 grade roots was at least 17% and 23% higher in Org-CCI and Org-NCC than Org-RT in 2001 and 2002, respectively, and similar to Conv in 2001 and 2004. Organic and conventional N sources contributed to soil inorganic N reserves differently the 2 years this component was measured. In 2002, soil inorganic N reserves at 30 DAT were in the order: Org-CCI (90 kg·ha<jats:sup>−1</jats:sup>) &gt; Org-NCC (67 kg·ha<jats:sup>−1</jats:sup>) &gt; Org-RT (45 kg·ha<jats:sup>−1</jats:sup>), and Conv (55 kg·ha<jats:sup>−1</jats:sup>). No differences in soil inorganic N reserves were observed among systems in 2004. Sweetpotato N, P, and K tissue concentrations were different among systems only in 2004. That year, at 60 days after transplanting, tissue N, P, and K were greatest in Org-CCI. In 2001 and 2004, N (4.09% to 4.56%) and K (3.79% to 4.34%) were higher than sufficiency ranges for N (3.2% to 4.0%) and K (2.5% to 3.5%) defined by North Carolina Department of Agriculture and Consumer Services recommendations for all treatments. No tissue macronutrient or micronutrient concentrations were limiting during this experiment. Reduced rainfall during the 2002 sweetpotato growing season may have contributed to the low microbially mediated plant-available N from the organic fertilizer sources. Despite differences in the nutrient content of organic and conventional fertility amendments, organically managed systems receiving compost with or without incorporated hairy vetch and rye produced yields equal to the conventionally managed system.</jats:p>

Effects of alternative cropping systems on globe artichoke qualitative traits

“…polyphenol and mineral content). We also assumed no significant differences in yield, as studies on other crops found that transition from intensive conventional cropping system to low‐input cropping system does not involve differences in terms of final yield . Currently the artichoke in the Mediterranean basin, of which Sardinia is a fully representative area, is grown according to traditional methods relying on monoculture systems .…”

“…We also assumed no significant differences in yield, as studies on other crops found that transition from intensive conventional cropping system to low-input cropping system does not involve differences in terms of final yield. [15][16][17][18] Currently the artichoke in the Mediterranean basin, of which Sardinia is a fully representative area, is grown according to traditional methods relying on monoculture systems. 19 The autumn-winter production is normally destined for fresh consumption, while that harvested during the spring period is used by the processing industry.…”

Green and animal manure use in organic field crop systems

“…The impact of rolling a rye + vetch mixture was compared to conventional tillage prior to applying PL on a subsequent sweetpotato crop in Florida in 2001, 2002, and 2004 (Treadwell, Creamer, Hoyt, & Schultheis, 2008). Yields tended to be lower in the rolled plots.…”

“…Aboveground DM production of species or mixtures was variable in many CGM studies in the southeastern United States (Parr et al., 2011; Reberg‐Horton et al., 2012; Treadwell et al., 2007, 2008; Vann et al., 2017). Endemic fluctuations in weather variables help explain this variation.…”

Hydrolyzed Organic Fish Fertilizer and Poultry Litter Influence Yield and Rhizosphere Ecology of Sweetpotato

“…Several studies have shown that organic production is comparable to conventional systems in terms of yield; however, organic systems had enhanced microbial biomass and activity, increased soil organic matter, increased nutrient pools, and other soil properties (Delate et al, 2003;Klonsky, 2000). A study comparing compost with or without cover crops and tillage on organic vs. conventional sweetpotato production showed that leaf N, P, and K concentrations were greatest in the compost/ cover crop combination compared with the other systems (Treadwell et al, 2008). Other studies found greater P, Mg, and Fe levels in organic systems and those mineral nutrients were on average higher in organically grown crops though results were somewhat inconclusive (Worthington, 2001).…”