Soil biological properties in multistrata successional agroforestry systems and in natural regeneration

Abstract

The diversity of cultivated plants in the agroforestry systems can create conditions to maintain the vital edaphic processes similar to natural regeneration areas. We studied agroforestry systems with five (AF5) and ten years (AF10) of age in comparison with natural regeneration areas for 10 years (NR) in the Atlantic Forest Biome in an area of environmental fragility. The microbial biomass carbon (MB-C), soil basal respiration (BResp), metabolic quotient (q-CO 2 ) and microbial quotient (q-mic) were evaluated in the entire profile of a Typic Udorthents, obtaining stratified data in the 0-2.5; 2.5-5; 5-10; 10-15; 15-30; 30-45 and 45-60 cm layers. The NR area had the highest MB-C (866 mg C kg -1 soil) and BResp (5 mg C-CO 2 kg -1 soil h -1 ) in the 0-2.5 cm layer in relation to the AF5 (686 mg C kg -1 soil; 4 mg C-CO 2 kg -1 soil h -1 ) and AF10 (478 mg C kg -1 soil; 4 mg C-CO 2 kg -1 soil h -1 ). However, the ratios did not differ among treatments, presenting average values in the profile of 7 mg C-CO 2 g -1 MB-C h -1 for q-CO 2 and 1.6 % for q-mic, demonstrating vital process similarity between systems. The phytosociological characteristics that interfere with the microbiological attributes were the plant species richness (0-2.5 cm) and plant diversity (2.5-5 cm). The epiedaphic fauna active in the litter was also assessed by pitfall traps and the average number of individuals per trap (238 for NR, 281 for AF5, 299 for AF10), the order richness (15 for NR; 14 for AF5, 13 for AF10) and relative frequencies did not differ among treatments, confirming that agroforests are in an ecosystem self-regulation condition function similar to natural regeneration, even with the removal of food products and income generation for the farmers.

Systemic Soil Fertility as product of system self-organization resulting from management

“…In successional agroforestry systems (SAFS), the greater addition of diversified plant material through pruning the vegetation, deposited onto the soil surface, is the key feature. This is because plant biomass catalyzes the ecological processes that ensure the self-regulation and sustainability of the system (Steenbock and Vezzani, 2013) and has a positive impact on the biological, physical and chemical properties of the soil (Cezar et al, 2015;Froufe et al, 2019), resulting in high productivity in lands normally characterized by low natural fertility. Intrinsic limitations in the sampling procedure refer to the representativeness of the area based on the collected soil sample.…”

Soil macrofauna as a bioindicator of soil quality in successional agroforestry systems

“…Organic matter often added to the soil provides a nutrient-rich substrate for soil fauna (Lima et al 2010;Martins et al 2019) and soil microorganisms, increasing nutrient cycling and soil fertility levels (Cézar et al, 2015).…”

Opportunities and challenges applying gene editing to specialty crops

“…The acronym SAF (an abbreviation of the Portuguese and Spanish words for "agroforestry system") has wide currency, and usually refers to multistorey systems of varying complexity. In Brazil, marketoriented systems may consist of intercropping three or more, mostly perennial, planted crops, for example cacao (Theobroma cacao), açai (Euterpe oleracea), black pepper (Piper nigrum), cupuaçu (Theobroma grandiflorum) or some timber species or oilseeds (Bolfe and Batistella, 2011), or much more complex high-biodiversity systems in which natural regeneration is managed, for example cabruca 49 systems (Sambuichi et al, 2012) and successional agroforests (Cezar et al, 2015).…”