605 Evaluation of How Cover Crop, Tillage, and N Fertilization Affect Nitrogen Sufficiency in Watermelons
Year: 1999
Type: article
Abstract: The effects of cover crop, tillage, and N fertilization on yields of `Paladin' watermelon ( Citrullus lanatus ) were analyzed by determining available soil N levels, foliar N content, and relative greenness with a SPAD-502 chlorophyll meter. Analyses from all three analytical procedures identified N deficiencies in watermelon with their respected measurements. Available soil N analyses indicated that soil N levels below 40 mg·kg –1 at vining caused dramatic decreases in yields, while the level needed to ensure maximal yields during the same period was 100 mg·kg –1 . Results from foliar and SPAD tests indicated that plants with foliar N levels below 42 g·kg –1 and SPAD readings below 40 SPAD units at anthesis will have suppressed yields. Optimal foliar N levels and SPAD readings required for maximum yields were 50 g·kg –1 and 48 SPAD units, respectively. The main difference among all three N testing procedures was that available soil N analysis was able to detect possible deficiencies two to three weeks before either the foliar or SPAD analysis. Differences in yield between plants from conventionally tilled plots and no-till plots were not significant. However, inorganic N fertilization significantly increased yields in watermelon following both rye ( Secale cereale ) and mix cover crop treatments. Watermelon yields of plants following the hairy vetch ( Vicia villosa ) cover crop treatment showed no response to inorganic N fertilization. Of the three cover crop treatments, the addition of N fertilizer had the most effect in the rye treatment.
Source: HortScience
Authors: Anthony F. Silvernail, Gary R. Cline
Language: English
Subfield: Soil Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: gold
Estimated APC paid: $3,000
OpenAlex ID: W2586601133