Responses of soil microbial biomass and N availability to transition strategies from conventional to organic farming systems [An article from: Agriculture, Ecosystems and Environment]
Book Details
PublisherElsevier
ISBN / ASINB000RR9D22
ISBN-13978B000RR9D29
AvailabilityAvailable for download now
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Agriculture, Ecosystems and Environment, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
Organic farming can enhance soil biodiversity, alleviate environmental concerns and improve food safety through eliminating the applications of synthetic chemicals. However, yield reduction due to nutrient limitation and pest incidence in the early stages of transition from conventional to organic systems is a major concern for organic farmers, and is thus a barrier to implementing the practice of organic farming. Therefore, identifying transition strategies that minimize yield loss is critical for facilitating the implementation of organic practices. Soil microorganisms play a dominant role in nutrient cycling and pest control in organic farming systems, and their responses to changes in soil management practices may critically impact crop growth and yield. Here we examined soil microbial biomass and N supply in response to several strategies for transitioning from conventional to organic farming systems in a long-term field experiment in Goldsboro, NC, USA. The transitional strategies included one fully organic strategy (ORG) and four reduced-input strategies (withdrawal of each or gradual reduction of major conventional inputs-synthetic fertilizers, pesticides (insecticides/fungicides), and herbicides), with a conventional practice (CNV) serving as a control. Microbial biomass and respiration rate were more sensitive to changes in soil management practices than total C and N. In the first 2 years, the ORG was most effective in enhancing soil microbial biomass C and N among the transition strategies, but was accompanied with high yield losses. By the third year, soil microbial biomass C and N in the reduced-input transition strategies were statistically significantly greater than those in the CNV (averaging 32 and 35% higher, respectively), although they were slightly lower than those in the ORG (averaging 13 and 17% lower, respectively). Soil microbial respiration rate and net N mineralization in all transitional systems were statistically significantly higher than those in the CNV (averagely 83 and 66% greater, respectively), with no differences among the various transition strategies. These findings suggest that the transitional strategies that partially or gradually reduce conventional inputs can serve as alternatives that could potentially minimize economic hardships as well as benefit microbial growth during the early stages of transition to organic farming systems.
Description:
Organic farming can enhance soil biodiversity, alleviate environmental concerns and improve food safety through eliminating the applications of synthetic chemicals. However, yield reduction due to nutrient limitation and pest incidence in the early stages of transition from conventional to organic systems is a major concern for organic farmers, and is thus a barrier to implementing the practice of organic farming. Therefore, identifying transition strategies that minimize yield loss is critical for facilitating the implementation of organic practices. Soil microorganisms play a dominant role in nutrient cycling and pest control in organic farming systems, and their responses to changes in soil management practices may critically impact crop growth and yield. Here we examined soil microbial biomass and N supply in response to several strategies for transitioning from conventional to organic farming systems in a long-term field experiment in Goldsboro, NC, USA. The transitional strategies included one fully organic strategy (ORG) and four reduced-input strategies (withdrawal of each or gradual reduction of major conventional inputs-synthetic fertilizers, pesticides (insecticides/fungicides), and herbicides), with a conventional practice (CNV) serving as a control. Microbial biomass and respiration rate were more sensitive to changes in soil management practices than total C and N. In the first 2 years, the ORG was most effective in enhancing soil microbial biomass C and N among the transition strategies, but was accompanied with high yield losses. By the third year, soil microbial biomass C and N in the reduced-input transition strategies were statistically significantly greater than those in the CNV (averaging 32 and 35% higher, respectively), although they were slightly lower than those in the ORG (averaging 13 and 17% lower, respectively). Soil microbial respiration rate and net N mineralization in all transitional systems were statistically significantly higher than those in the CNV (averagely 83 and 66% greater, respectively), with no differences among the various transition strategies. These findings suggest that the transitional strategies that partially or gradually reduce conventional inputs can serve as alternatives that could potentially minimize economic hardships as well as benefit microbial growth during the early stages of transition to organic farming systems.
