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The Sustainable Agriculture Farming Systems (SAFS) Project was established in 1988 to study the transition from conventional to low-input and organic farm management in California's Sacramento Valley. We evaluated the effects of these alternative farming systems on soil compaction, water-holding capacity, infiltration, and water storage in relation to tomato yield and fruit quality within the SAFS cropping systems comparison 10 years after it had been established. Soil bulk density (0-15, 15-30, 30-45, and 45-60 cm) was not significantly different among the farming systems. In situ water-holding capacity at 24, 48 and 72 h after water application was significantly higher in the organic system at all times and depths except 45-60 cm. Cumulative water infiltration after 3 h in the organic and low-input cover crop-based plots was more than twice that of the conventional system. The more rapid infiltration in the low-input and organic systems resulted in increased total irrigation needs, more water stored in the soil profile throughout the 30 days before harvest, and lower fruit soluble solids and titratable acidity in these systems relative to the conventional system. Yields were not significantly different in the organic, low-input, and conventional systems during either 1997 or 1998.
Rooted cuttings of `Supjibi' poinsettia were potted in peat vermiculite, mixed with coal bottom ash at 0%, 25%, 50%, 75%, or 100% by volume. Values of pH were higher in media containing coal bottom ash. In general, pH increased for the first 4 weeks, during which time 50–100 ppm (N) fertilizer was being applied, decreased temporarily when 200 ppm fertilizer began, and then increased and stabilized for the last 5 weeks. At first, pH tended to be higher with increase in ash, but when 200 ppm fertilizer was begun, pH became the same in all coal ash levels. Once fertilization was stopped, pH tended again to be higher in ash media. Levels of EC remained low in all media when 50–100 ppm of fertilizer was applied, but increased after 200 ppm fertilizer was begun, increasing to excessive levels 2 weeks later. With more watering, EC declined in the 0% ash, but remained high in 50% to 100% ash media. Leaf Ca content increased with increase in media ash but was below the normal range in all plants. With increase in media ash, water capacity decreased, but bulk density increased. Bract color development in plants in ash media appeared delayed.
. (1997) measured clay swelling behavior in situ. Like in soil studies, the physical properties of growing media used in horticulture are usually characterized by the water retention curve obtained during a drying process according to standardized
The most common substrate used in horticulture for growing seedlings and soilless plants cultivation is peat, alone or in mixture ( Chavez et al., 2008 ), because of its good chemical and physical properties. Unfortunately, peat is a very expensive
to determine basic physical properties [total porosity (TP), AS, and CC] of a substrate for a specific size and shaped container ( Bilderback and Fonteno, 1987 ; Milks et al., 1989b ). Container size has been proven to significantly alter substrate
to improve the physical properties of compacted soils. In compacted soils, tillage breaks up massive structure, thereby increasing soil pore space and allowing water to infiltrate and roots to penetrate through the soil profile ( Lipiec and
-Kristensen (2005) assessed the suitability of miscanthus clippings for use as a container substrate by measuring various physical properties of this material and other composted crop residues. Their ( Dresboll and Thorup-Kristensen, 2005 ) research did not include
compaction can damage soil physical properties and inhibit turfgrass root growth as well as visual quality ( Turgeon, 2005 ). A past study proved that warm-season turfgrass species have a greater tolerance to wear compared with cool-season ones ( Shearman and
Organic amendments, including municipal and animal sources of biosolids, can be applied to improve soil physical and chemical properties and turfgrass establishment, growth, and quality ( McCoy, 1998 ). Although the amendments contribute total and
water availability in the rhizosphere strongly depend on the physical properties of the substrates, which in turn are conditioned by the shape and size of their constituent particles ( Da Silva et al., 1993 ; Hanan et al., 1981 ; Raviv et al., 2002