The effects of mulching on crops, horticultural in particular, pathogens, pests and weeds have been extensively studied. In contrast, the mulching effects on soil physical and chemical characteristics have been less investigated. The aim of this bibliographic review is to analyze and synthesize relevant works carried out mainly in the last decade on the main effects of different types of inorganic and organic mulches on moisture, temperature, structure and salinity of agricultural soils. First, the different types of mulches most commonly used in irrigated agriculture are discussed. Plastic mulches are most widely used because they are the cheapest, but their intensive use is causing soil contamination due to their high stability and persistence of residues. Hence, plastic is being progressively substituted by other alternative biodegradable materials of organic (straw, pine bark, paper) or mineral (geotextiles) type. Secondly, the results about the effects of different types of mulches on several soil variables are summarized. Mulching reduces water evaporation from the soil surface, maintains higher soil moisture content, promotes the structural stability and fertility of soils and reduces evapoconcentration and soil salinization. Also, from a thermal point of view, organic mulches decrease soil temperature fluctuations whereas plastic mulches favour soil warming which may lead to a beneficial precocity of certain horticultural products.