A Nematode Community-Based Integrated Productivity Efficiency (IPE) Model That Identifies Sustainable Soil Health Outcomes: A Case of Compost Application in Carrot Production

Abstract

Percent soil organic matter (SOM), pH and crop yield are among the biophysicochemical process-driven soil health indicators (SHIs). However, identifying sustainable soil health conditions using these SHIs is limited due to the lack of Integrated Productivity Efficiency (IPE) models. We define IPE as a concept that identifies best-to-worst-case soil health outcomes by assessing the effect of agronomic practices on weighted abundance of functional guilds (WAFG) of beneficial soil organisms and SHIs simultaneously. Expressing WAFG of all beneficial nematodes (x-axis) and SHIs (y-axis) as a percent of untreated control and regression of x and y reveals four quadrants describing worst-to-best-case outcomes for soil health and sustainability. We tested the effects of composted cow manure (AC) and plant litter (PC) applied at 135 (1×), 203 (1.5×), and 270 (2×) kg N/ha on WAFG, SOM, pH, and yield in a sandy clay loam field of a processing carrot cultivar over three growing seasons. Untreated control and urea at 1× served as experimental controls. Data that varied by time and were difficult to make sense of were separated into sustainable, unsustainable, or requiring specific modification to be sustainable categories by the IPE model. Within the sustainable category, all AC treatments and 2× rate of PC treatments had the best integrated efficiency outcomes across the SHIs. The IPE model provides a platform where other biophysicochemical process-driven SHIs could be integrated.

Understanding the dynamic interactions of root-knot nematodes and their host: role of plant growth promoting bacteria and abiotic factors

“…Agricultural practices (APs) modulate the host-RKN-PGPB interactions by affecting plant and RKN development as well as altering soil’s physicochemical and biological properties ( Habteweld et al., 2022 ). Common APs in conventional agriculture such as tillage, the use of inorganic fertilizers, and chemical pesticides and herbicides, may increase plant growth but often have harmful effects on the environment and human health ( Lal, 2008 ; Diacono and Montemurro, 2010 ).…”

“…In contrast, cultural APs such as organic amendments, mulching, crop rotation, cover cropping and conservation tillage increase the availability of nutrients, improve soil structure leading to better moisture retention and soil microbial activity, reduce fertilizer loses to the environment, and increase plant growth ( Oquist et al., 2007 ; Forge and Kempler, 2009 ; Glover et al., 2010 ; Zhang et al., 2014 , 2016 ; Habteweld et al., 2020a , 2020b ). Compost stands as one of the most widely employed organic amendments, demonstrating its ability to enhance soil organic matter, augment nutrient content, stimulate microbial activity, suppress pests, and contribute to overall soil health improvement ( Bulluck et al., 2002 ; Forge and Kempler, 2009 ; Ferris et al., 2012 ; Habteweld et al., 2018 , 2022 ). Incorporating compost as soil amendment increases soil pH by forming an aluminum complex and increasing base saturation ( Shiralipour et al., 1992 ; Van den Berghe and Hue, 1999 ).…”