The imaging and analysis approach developed based on calibrated in vitro measurements was extended to in-vivo data. Bending and tension forces were successfully evaluated in this pilot study.
Core Ideas
Poultry feather meal is acceptable in organic flue‐cured tobacco production.
Application rates of organic N should reflect those in conventional production.
Soil moisture is critical for N mineralization and assimilation.
Information on N management in organic flue‐cured tobacco production is limited. Research was conducted from 2012–2013 to determine the effects of two certified organic N sources applied at three rates on the yield, quality, and chemical constituents of flue‐cured tobacco. These organic N sources included Nature Safe 13–0–0 (NS) and Nutrimax 12–1–0 (NM), both of which consisted of hydrolyzed poultry feather meal. Application rates for both fertilizer sources were 17 kg N ha−1 above recommendation (B+), at recommendation (B), and 17 kg N ha−1 below recommendation (B–). A conventional control containing urea‐ammonium‐nitrate (UAN) was applied at the B application rate. Tobacco yield and quality were similar among conventional and organic N programs. Leaf N concentration, SPAD measurements at flowering, and total alkaloid concentration of cured leaves responded positively to increased N application rates, regardless of organic fertilizer source. The largest increases in nitrogenous‐based leaf constituents were observed in this study where B+ treatments were applied; however, those increases did not translate into increased leaf yield or quality and could delay the initiation of leaf senescence in growing seasons with low soil moisture. Results from this study demonstrate the acceptability of poultry feather meal sources for organic tobacco production, and confirm that application rates of organic N sources should follow conventional recommendations.
Optimal application methods of organic poultry feather meal for flue-cured tobacco (Nicotiana tabacum L.) production are unknown. Research was conducted in 2012 and 2013 to quantify the effects of two poultry feather meal sources, 13-0-0 Nature Safe and 12-1-0 Nutrimax, applied using three different methods: 100% broadcast before transplanting, 50% broadcast before transplanting + 50% sidedress, 10 d after transplanting, and 100% sidedress 10 d after transplanting. A conventional N treatment comprised of 28% liquid urea-ammonium nitrate (UAN) was split-applied 10 d after transplanting and at layby. Leaf yield was similar between each individual organic N treatment and UAN. Nature Safe applied 100% sidedress resulted in leaf N concentration and cured leaf quality similar to UAN. In the absence of the UAN treatment, application method typically had a greater impact on measurements than feather meal source. Leaf N concentration was generally increased with the 100% sidedress application, most likely due to closer nutrient proximity relative to roots. Increased N assimilation from 100% sidedress treatments also produced a slightly darker leaf color as quantified by Soil Plant Analysis Development (SPAD) measurements and a higher total alkaloid concentration in cured leaves. Leaf yield was similar among application methods in 2012, but was highest in the 100% sidedress treatment in 2013 due to high early season rainfall. Results from this study demonstrate the effectiveness of both feather meal sources and that 100% sidedress applications may prove ideal under a range of environmental conditions commonly encountered in North Carolina.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.