Amelioration of degraded soils is time-consuming and expensive. Green manure and cover crops have been widely used in this remediation process since these plants produce a large amount of phytomass at a low cost, especially if they are tolerant to soil acidity. This study was carried out to evaluate the effect of liming on dry matter yield of the following 16 species, under greenhouse conditions: eight winter crops (Lollium multiflorum, Avena strigosa, Lathyrus sativus, Lupinus angustifolius, Pisum sativum, Secale cereale, Vicia sativa and Vicia villosa); and eight summer crops (Stizolobium niveum, Stizolobium aterrinum, Stizolobium deeringianum, Crotalaria juncea, Crotalaria retusa, Crotalaria spectabilis, Cajanus cajan and Canavalia ensiformes), grown in two acid south Brazilian soils (Haplumbrept and Hapludox), in Lages (SC), in 1997. Treatments consisted of dolomitic limestone rates equivalent to 0, 0.25, 0.50, 1.00 and 1.50 times the amount indicated by the SMP method to increase soil pH to 6.0. Exchangeable Ca and Mg increased linearly with liming, and at similar rates (about 3.0 mmol c kg-1 per 0.1 pH unit). The effect of liming on dry matter yield varied with soil and especially with plant species. Dry matter yield of ten species was not affected by liming in, at least, one soil, and only five species had similar response to liming on both soils. The soil pH for maximum yield was always equal to or below 5.5, regardless of soil type. Crop yield was higher and crop response to liming was normally lower on Haplumbrept than on Hapludox, probably due to the positive effect of soil organic matter, which was higher on Haplumbrept. These species may, thus, be successfully cultivated to improve the physical, chemical and biological properties of degraded acid soils, requiring for maximum yield less limestone than the present regional recommendation rates.
green manure; cover crops; liming; soil acidity