Florida vineyard soils are characterized by poor soil fertility; the soil is highly susceptible to erosion ( Collins, 2017 ; Gillette and Walker, 1977 ; Marchi et al., 2016 ) and has low organic matter contents ( Brown et al., 2018 ), nutrient and water
systems, cultivated muck soils may subside up to 3 cm every year because of wind erosion, compaction, and organic matter oxidation ( Hoffmann et al., 1996 ). A cover crop planted after harvest of the cash crop may help reduce soil erosion and compaction
Sunn hemp, Crotalaria juncea L., is a warm-season legume that is planted before or after a vegetable cash crop to add nutrients and organic matter to the soil ( Cherr et al., 2006 , 2007 ; Mansoer et al., 1997 ; Wang et al., 2005 ). This cover
Management practices that build soil organic matter (SOM) are valuable for improving soil water-holding capacity, nutrient retention, aeration, and infiltration rates ( Magdoff and van Es, 2000 ) . For carrots ( Daucus carota subsp. sativa), these
adaptation ( Penella et al., 2015 ). Cultivated blueberry ( Vaccinium species) have strict soil requirements for optimum growth. These include low pH (4.0–5.5), high organic matter, good aeration and drainage ( Williamson et al., 2018 ), and readily
al., 2009 ; Strik and Buller, 2014 ). Soils suitable for blueberry production must be acidic (pH 4.0 to 5.5), well aerated with good drainage, high in organic matter ( Williamson et al., 2012 ), and have readily available iron (Fe) and ammonium
N plus the inorganic N (NH 4 -N and NO 3 -N) ( Campbell-Nelson, 2015 ). Table 1. The carbon to nitrogen ratio (C:N), organic matter (OM), total C, organic N, nitrogen as ammonium (NH 4 -N), nitrogen as nitrate (NO 3 -N), phosphorus (P), and potassium
, hydrolyzable nitrogen, rapidly available phosphorus, rapidly available potassium, and organic matter) and soil physical properties (clay content and soil density) for the 0- to 25-cm soil layer were analyzed by the Tianjin Institute of Resource and
Two on-farm field studies were conducted in 1996 and repeated in 1997 to determine the effects of soil amendments and scape (flower stalk) removal on yield, dry matter partitioning, and storage quality of hardneck garlic (Allium sativum L.). One study site was on a loamy sand soil with low organic matter and fertility and the other site was on a sandy loam soil with high organic matter and fertility. Soil amendment treatments tested at both sites were: 1) no amendment, 2) composted manure, and 3) inorganic fertilizer according to soil test recommendations. A fourth treatment, dried, composted turkey-manure-based fertilizer, was included at the low organic matter site. Scapes were removed at the curled stage from plants in half of the harvest rows. Scapes from the remainder of the harvest row plants were allowed to mature until harvest. In 1997, bulbs from each treatment were stored at 0 to 3 °C or 19 to 21 °C for 6 months. Soil amendment treatments had no effect on total garlic bulb yield, dry mass partitioning, or stored bulb weight loss at the sandy loam, high organic matter site. Manure compost, fertilizer, and composted turkey manure soil amendments reduced the yield of smaller bulbs compared with the control at the loamy sand, low organic matter site. The proportion of bulbs >5 cm was highest with the manure compost treatment. At the low organic matter site, scape removal resulted in a 15% increase in bulb yield and an increase in bulb size compared with leaving scapes on until harvest (P = 0.05). At the high organic matter site, scape removal increased bulb yield by 5% (P = 0.10). Scape removal increased dry matter partitioning to the bulbs, but had no effect on total (scape + shoot + bulb) aboveground dry matter production. The increase in bulb dry mass when scapes were removed was offset by an increase in scape dry mass when scapes were left on. Bulb weight loss in storage was less at 0 to 3 °C than 19 to 21 °C. Soil amendments only affected bulb storage quality at the loamy sand, low soil organic matter site. The effect of scape removal on bulb weight loss was nonsignificant at either location.
organic matter and ash that remains after organic matter is thermally decomposed in a low-oxygen environment ( Lehmann and Joseph, 2009 ). Biochar addition has been shown to impart beneficial chemical and physical attributes to mineral soils ( Barrow, 2012