Potential Changes in Net Primary Productivity and Carbon Input of Periurban Agroecosystems Treated with Biosolids in Buenos Aires, Argentina

Biosolids application in periurban agroecosystems could mitigate climate change by sequestering C, while improving plant net primary production (NPP). Monitoring NPP is useful for studying ecological responses to human management. The values of NPP and C input in periurban agroecosystems are insufficient or missing. The objective was to use local databases to estimate NPP and C input in periurban areas (south, north and west) of Buenos Aires City, Argentina, using different biosolids application scenarios (low and high effects). The NPP varied with crop and vegetable types (P < 0.05), with maize (Zea mays) and wheat (Triticum aestivum) presenting the highest production, soybean (Glycine max) medium and sunflower (Helianthus annuus) the lowest. Tomato (Lycopersicon esculentum Mill.) presented the highest production in the south area (La Plata). West and north areas, where Vertic and Typic Argiudolls are the main soils, presented the lowest NPP and C input. According to the low and high effect scenarios, only vegetables presented significant differences (P < 0.05) in average and cumulative NPP and C input between areas. Vegetables contributed with the highest proportion (> 70%) to NPP in both projected scenarios. For both scenarios, average C input by crops and vegetables presented similar proportions. Biosolids addition in periurban agroecosystems could be a viable practice to elevate NPP and C input.