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The influence of sugar foam amendment on the moisture-retention properties of three profiles of an acidic vineyard soil in Retuerta del Bullaque (Ciudad Real, Spain) has been studied. The values obtained for the surface horizons of modified soils and the original soil (under natural vegetation) were compared, as were those for the surface and subsurface horizons of the liming profiles. The water-retention curves (drying curve) were determined in triplicate on the sieved soil with Richards plates and the field capacity (FC), permanent wilting point (PWP), and available water-retention capacity (AWRC) were calculated. In the original soil FC, PWP, and AWRC values were greater than the average values for the amended soils (36.5 percent, 15.1 percent, and 21.5 percent versus 23.5 percent, 10.35 percent, and 13.1 percent, respectively). Comparison of the surface horizons and the subsurface horizons of the three profiles showed that the values for the AWRC were greater in the former (13.1 percent, 12.5 percent, and 14 percent for P1, P2, and P3, respectively) than in the latter (11.9 percent, 9 percent, and 8.6 percent for P1, P2, and P3, respectively), although FC and PWP were lower in A horizons than in B horizons. [ABSTRACT FROM AUTHOR]

After decades of tillage, the pH and organic matter content of frail acid soils in the west and south west of Spain have dropped to critical values severely limiting the grain and pasture yields. The aim of this work was to quantify the economic feasibility of applying sugar factory lime foam (SF) in the representative acid soils studied (Plinthic Palexerult). Yields significantly increased with liming with SF at 7.4 t ha−1. The useful life of the amendments was estimated at a minimum of nine years. The mean yield of biomass in the treated plots from cereal or a mixture of cereal and vetch in the last seven seasons was of 5306 kg dry matter ha−1. The mean biomass collected represented 2.7 times that obtained in untreated control plots and 4.7 times the mean yield of natural pasture fields. Once all the liming expenses (25 € t−1) and the complementary fertilization were evaluated, it was observed that the net income obtained by farmers with the increase in the hay yield (0.084 € kg−1 dry matter) over the control plots paid off the investment made in two seasons. This assay demonstrates that it is feasible to multiply hay yields in the degraded Ultisols of Spain. [ABSTRACT FROM AUTHOR]

This article aims to compare the effects of applying three doses of sewage sludge, with or without liming, on organic matter, total and available chromium (Cr), and their concentration in plants. Unfertilized (NF) and mineral treatments were used as control. Soil organic-matter (SOM) modification depended on the interaction of liming and sewage sludge implementation. Liming, high sludge doses, and mineral treatment caused less SOM in the second year of study. However, after 3 years, SOM was increased by both mineral and sludge fertilizers compared to NF treatments as result of tree development and the reduction of organic-matter mineralization into the soil. These findings could have important implications for soil carbon storage capacity. Total Cr in soil and forage was increased by sewage sludge application compared to mineral or NF treatments. Liming increased Cr availability in the spring of 2000, where sewage sludge was applied, and reduced Fe availability. [ABSTRACT FROM AUTHOR]

Abstract: A laboratory experiment involving the use of leaching columns reproducing the topmost portion of a Hyperdystric Acrisol (FAO 1998) or plinthic Palexerult (Soil Survey Staff 2003) treated in its Ap horizon with sugar foam wastes and phosphogypsum was conducted. The amendments increased the contents in exchangeable calcium (Ca) of the Ap horizon and, to a lesser extent, also that of the AB horizon. However, the contents in exchangeable magnesium (Mg) and sodium (Na) decreased as much in Ap as they did in AB; by contrast, the potassium (K) content exhibited a less marked decrease. The potassium chloride (KCl)-extractable aluminium (Al) of the Ap horizon was dramatically decreased much more than that of the AB horizon by the amendments. In the soil solution from Ap, the amendments raised the pH and decreased the Al concentration; in that from AB, however, they caused an initial pH decrease, a tendency that reversed as the gypsum was leached and eventually led to the pH exceeding that in the soil solution from control. The first few water extractions exhibited increased Mg concentration. This trend was reversed in the second leaching cycle, where the concentrations of Mg in the amended columns were lower than those in the controls. In the soil solution, the variation of the Ca and sulphate (SO4 2-) concentrations was influenced by the salt-sorption effect. The total Al content in soil solution from AB increased during the first leaching cycle and then decreased during the second. The amendments decreased the activities of Al3+, AlOH+2, and Al(OH)2 + in the Ap horizon and increased those of Al3+, AlSO4 +, Al(SO4)2 -, and AlF+2 in the first leaching cycle in the AB horizon. The productivity of the Ap horizon after the treatments was assessed using a wheat crop (T. aestivum, var. 'Jabato') in a greenhouse. [ABSTRACT FROM AUTHOR]