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Composting is the most recommended organic waste management technique worldwide. These residues can have various origins, they can even be the result of the industrial processing of agricultural products, such as alperujo, which results from the extraction of oil from olives. This residue, once composted, has the potential to generate a compost of good quality that can be used as an amendment and / or organic fertilizer. However, little information exists regarding the quality of the compost made from alperujo with pruning remains from olive groves. The objective of the present work was to characterize physically, chemically and microbiologically the compost obtained from the composting of olive residues, both in the solid (AS) and liquid (AL) form. In addition, the presence of phytotoxic substances was analyzed through the germination test with different horticultural species. The trials comprised four productive periods. The chemical, physical and microbiological evaluated parameters (organic carbon, pH, electrical conductivity, nitrogen, phosphorus, potassium, soluble cations, polyphenols, biological activity, bulk density, particle density, porosity) are within the range considered adequate in both AS and AL. Phytotoxic effects of LA were not detected in the evaluated species. The results indicate that both fertilizers present highly recommended characteristics for their use as amendment and / or organic fertilizer, and that AL is capable of promoting germination in spinach, parsley, basil and alfalfa. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the impact of different rates of poultry biochar on soil chemical and microbiological properties under a land-use intensity gradient. Three sites were selected: a pristine forest soil (SP), an agricultural soil under sustainable management (MS), and an agricultural soil under conventional tillage (LI). The biochar was applied at four different rates: without biochar (control 0%) and biochar at 1%, 3% y 10%. Poultry biochar increased pH, electrical conductivity (CE), total organic C (COT), and C/N ratio. In general, biochar applied at the highest rates increased the hydrolysis of fluorescein diacetate, suggesting an increase of total microbial activity. However, biochar applied at the highest rates significantly decreased dehydrogenase activity, mainly under MS and LI. Furthermore, an increase of actinobacteria and mycorrhizal fungi were observed in soils treated with the highest rate of biochar. In general, biochar tended to increase Gram-negative bacteria compared to control. Our study also showed an increase of total phospholipids fatty acids (PLFAs) in SP and LI, indicating that biochar can increase total microbial biomass. For this reason, the application of biochar could be of greater utility in the remediation of soils with a high level of edaphic degradation. [ABSTRACT FROM AUTHOR]

Supplementary irrigation increases and stabilizes crop yields. However, when irrigation water of poor quality is applied, it can adversely affect soil properties. The objective of this study was to: evaluate the influence of supplementary irrigation on some physical and chemical properties under no- till cultivation systems. A field experiment was performed on a loamy Typical Argiudoll, managed under no- tillage. The treatments were: 1-Irrigated soil during 13 years, 2-Adjacent Rainfed soil. Soil chemical (pH, electric conductivity, exchangeable sodium percentage, organic carbon, total N, exchangeable cations, cation exchange capacity, extractable P) and physical properties (infiltration rate, soil penetration resistance, bulk density, gravimetric water content, structural instability) were evaluated. Irrigation significantly increased the pH and exchangeable sodium percentage (P<0.05), while electric conductivity was slightly affected. Although the mean soil infiltration rate in the Irrigated treatment was lower than in the Rainfed one, it was not able to detect significant differences between treatments because of the high variability in the irrigated treatment. Regarding soil physical properties, supplementary irrigation did not affect bulk density. Soil penetration resistance (0-40 cm) was high (> 2Mpa) in both treatments, probably due to the effects of the cultivation and harvest machinery under high soil water contents. The soil structural instability was very low (i.e. high structural stability) in both treatments, probably associated to the high organic matter content and the no- till cultivation system. [ABSTRACT FROM AUTHOR]

Austrocedrus chilensis forests suffer a widespread mortality locally known as «mal del cipré controversial. Previous studies suggested Phytophthora austrocedrae as the biotic cause; how studied since there are affected areas not connected with Phytophthora. The soil was prov disease. The purpose of this article was to study soil chemical properties related to A. chi chilensis dense forests developed on different types of soils were selected in the 16 de Oct In each of them, pairs of plots that differed in disease symptoms were established. Each pa of disease (diseased plot) and another that did not exhibit symptoms (asymptomatic plot forests, where the disease was totally absent. In each plot, a soil sample from the A horizon study showed high soil chemical fertility in all the forest soils, with high contents of organic m high cation exchange capacity. Differences between diseased forests and control forests we of bases, base saturation, calcium, pH NaF and phosphorus. These differences could be associ also be associated to the presence of Phytophthora. [ABSTRACT FROM AUTHOR]

During the last decade, the soil use intensification, the high nutrient extraction rates and the excessive use of nitrogen fertilizer have increased the degradation of Santa Fe soils. The objective of this study was to quantify the differences among cultivated soils (SC) and their respective non-cultivated situations (SNC) for diverse chemical and biological attributes. The following properties were evaluated in typical and aquic Argiudolls of the center of Santa Fe:,organic matter (MO), pH, exchangeable bases (calcium, magnesium, sodium and potassium) and cation exchange capacity (CEC) in two depths (0-15 and 15-30 cm). The comparison between SNC and SC showed that, in both depths, a decrease took place of the values of MO (near 30%), calcium (20%), magnesium (30%) and pH (up to 0,6 units in the 0-15 cm layer). The exchangeable potassium and the cation exchange capacity showed significant decreases in SC compared to SNC only in the 0-15 cm layer. The actual content of K corresponds to 64% of the original value. The exchangeable sodium was the only chemical parameter that did not show a significant alteration due to the soil use. The results of this study confirm that the Argiudolls of the center of Santa Fe suffered a significant change in some of their properties in relation to their natural situation. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the best indicators of soil quality in a central area of Córdoba Province. The study was carried out on a Typic Haplustol. Six treatments were evaluated in three sites for each treatment. Organic carbon content (CO), total nitrogen (NT), pH, electrical conductivity (CE), extractable phosphorus (PE), light carbon, humic and fulvic acids, bulk density, mean weight diameter change (CDMP), A-horizon thickness (HzA) and CaCO3 depth were determined. Principal Component Analysis was used to evaluate the relationship between soil parameters, between parameters and treatments and between treatments. The results show that the most adequate soil quality indicators --and the simplest- are those related to soil fertility: organic matter, total nitrogen and extractable phosphorus; and to susceptibility to erosion (CDMP, CaCO3 and A-horizon thickness). The decrease in CO content and its fractions and in macronutrients (NT and PE) and the increase in susceptibility to hydric erosion over the years as a consequence of agricultural practices such as soybean monoculture and traditional sowing have led to a deterioration in soil quality compared to native woodlands where the soil potential is higher. Under semi-arid conditions, direct sowing did not improve the physical properties of the soil or its organic content and fractions under a soybean monoculture. [ABSTRACT FROM AUTHOR]

The relationships among location, mean annual precipitation and nine edaphic variables were studied for 95 profiles of volcanic soils throughout the Andean Region of the provinces of Neuquen, Rio Negro and Chubut. A cluster analysis conducted with the edapbic variables at two depths (0-20 cm and 30-60 cm) indicated five main groups. Principal component analysis (PCA) allowed to differentiate the groups for the axis 1. This axis was positively related to longitude, indicating an increase of pH (NaF), organic C and water retention capacity, and a decrease of pH (H20), pH (KC1) and bulk density from the xeric steppe soils at east to the udic forest soils at west. [ABSTRACT FROM AUTHOR]