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An increasing area of marginal agricultural land in the coastal plain of the southeastern United States is being planted to longleaf pine (Pinus palustris Mill.). This chronosequence study in southern Georgia evaluated the effect of pine planting and the associated cessation of agricultural activity such as tillage and fertilization on soil C storage and soil nutrient stocks. Soils are Arenic or Typic Kandiudults with coarse‐textured surface soils. Soil C, nutrients, and bulk density from 0 to 50 cm in planted stands 1, 3, 7, and 14 yr old, as well as soils beneath natural longleaf pine stands that were in a never tilled (NT) condition, were evaluated (n = 3 per stand age). No accumulation of soil C was apparent during the first 14 yr of pine growth. The average content of soil C in planted stands (11 ± 1 Mg/ha; mean ± 1 se) was ∼16 Mg/ha less than that in the NT soils (27 ± 4 Mg/ha). Soil total N content within planted stands also did not differ by age, although extractable NO3 declined rapidly. Despite agricultural N inputs, the mean N content of planted stands (410 ± 83 Mg/ha) was below that in NT stands (730 ± 21 Mg/ha). Total P (1507 ± 21 Mg/ha) and extractable P (113 ± 21 Mg/ha) contents also did not differ between planted stands but had highly elevated values compared to total P (728 ± 38 Mg/ha) and extractable P (2 ± 1 Mg/ha) for NT soils. Soil exchangeable Ca, Mg, and K had generally decreasing contents with stand age but varying patterns related to NT soils. During the first 14 yr of reforestation, soils did not sequester C. Carbon benefits may be gained, however, in aboveground and belowground biomass accumulation and through the cessation of high energy‐consumptive activities such as fertilization or tillage. Enhanced P fertility on these marginal lands can improve pine growth, but only if other elements such as N are not limiting to growth.

Cercospora kikuchii, involved with the defoliation of soybean (Glycine max) plants, is normally associated with Septoria glycines in late season. Seventy-two isolates from different regions in Brazil, obtained mainly from purple stained seeds, showed phenotypic variation. Cercosporin content and rate of colony growth was higly variable among isolates. A strong correlation between cercosporin content and virulence was identified. Genetic variation among and within populations was evaluated based on 86 RAPD loci. The RAPD analysis clustered all isolates into seven groups. No relationship was observed between RAPD groups and geographic origin or cercosporin content. The sequence of the internal spacer regions (ITS1-5.8S-ITS2) from 13 isolates chosen according to the previous RAPD and clustering analysis showed high similarity (97%-100%) to the GenBank sequences of C. kikuchii (AY266160, AY266161, AY152577 and AF291708). It is clear from this work that Brazilian isolates of C. kikuchii from different geographic regions, are variable in relation to virulence, RAPD profiles and cercosporin content. Cercosporin content could be a good parameter for choosing an adequate isolate for screening resistant or tolerant cultivars. Considering that this pathogen is easily seed-borne, findings are expected to show the same haplotypes in different regions. Migration could be favoured by infected seeds as demonstrated by RAPD analysis.