Is there a correlation between soil health (or soil productivity) and manure? A Missouri team analyzed many soil health related variables and manure land application details, based on data collected under the Missouri Cover Crop Cost-Share Program and experimental plots. Continue reading
This article was originally published by iGrow.org on 12/27/17 and shared here with permission.
Empower Educators to Improve Water Quality by Adoption of Soil Health Practices
In December, I traveled to Indianapolis, IN to attend a meeting sponsored by the North Central Region Soil Health Nexus. The meeting was a kickoff to discuss a new grant the Nexus was recently awarded entitled “Empower Educators to Improve Water Quality by Adoption of Soil Health Practices.” Continue reading
Soil health management refers to the preservation and improvement in soil physical, chemical, and biological properties to maximize the productive capacity of soil. Cover crops and reduced tillage are promoted for improving soil health; however, soil amendments such as application of livestock manure and municipal biosolids have received less attention as a soil health improvement practice. A literature review, funded by the North Central Region Water Network and the Soil Health Institute, was conducted to summarize and discuss results of studies reporting chemical, physical, and biological soil properties from application of livestock manure, animal by-products (i.e. compost), and municipal biosolids and to identify further research needs.
Current State of the Science and Understanding
The effects of manure and municipal biosolids on soil physical and chemical properties are well documented in scientific literature (and previously in this blog). When applied at agronomic rates, these amendments:
- increase soil organic carbon,
- increase soil cation exchange capacity,
- provide beneficial micronutrients for crops,
- decrease soil bulk density,
- improve soil resistance to compaction,
- increase soil aggregate stability,
- increases water retention and plant available water, and
- increase water infiltration, which reduces risks for runoff and erosion.
The effects of these amendments on soil biological properties have not been, however, well researched, likely due to cost and time constraints for these measurements. Three main soil biology measures are microbial abundance, diversity, and activity, with abundance being the most commonly reported. These reveal the types (diversity), quantity (abundance), and roles (activity) of soil microbes. Overall, manure and biosolid applications increase the abundance of bacteria, fungi, and earthworms but does not affect abundance of higher order soil microarthropods (i.e. shredders and predators) (figure 1). Increased microbial activity (e.g. respiration and mineralization), an indicator of nutrient cycling, increases with organic amendments; however, faunal diversity does not appear to be positively impacted compared to inorganic fertilizer.
Challenges and Research Needs
Most published research reporting on the impacts of manure or biosolids on soil properties, crop production, and water quality is based on studies involving annual application of the amendment. If annual application rates exceed crop nutrient requirements, risks of leaching, runoff, and accumulation of nutrients (e.g. N, P, K, salts and heavy metals) increase. While few studies have investigated the residual effects of manure or biosolids, improved infiltration and decreased runoff and erosion have been demonstrated to have enduring effects in the years immediately following the last manure application.
Future research endeavors should:
- incorporate quantification of soil biological metrics to improve understanding of manure and biosolids effects on ecosystem services such as nutrient cycling;
- investigate short- and long-term effects of a single manure or biosolids application to support identifying the optimal frequency of application for soil health and
provide discussion clearly relating research findings to management decisions relevant to agricultural crop producers.
Reviewer: Humberto Blanco, University of Nebraska-Lincoln
Farmers and ranchers are becoming increasingly aware of the importance of soil quality/health to the productivity and sustainability of their agricultural system. Research and field observations have demonstrated that carefully managed manure applications can contribute to improved soil quality with limited environmental and social risks. However, a comprehensive assemblage of outputs and conclusions from research studies, field trials, soil labs databases, and other sources has never been developed. Continue reading
Tunsisa Hurisso and Steve Culman, School of Environment and Natural Resources, Ohio State University
In short, the answer is usually both.
Soil organic matter is a mixture consisting of various compounds (e.g. simple sugars, cellulose, proteins, etc.) derived primarily from plants and microbes. It represents 1-6% by mass of agricultural soils, but plays a disproportionate role in soil function. Organic matter in soils acts like a sponge, holding nutrients (sequestration or stabilization) that become available to plants when organic matter is broken down (mineralization) by the collective action of the soil food web (mainly by bacteria and fungi). In addition to nutrients, organic matter also enhances the soil’s water holding capacity, making farmlands more resilient to periods of drought. In contrast, when organic matter is depleted due to repeated plowing and/or removal of crop residues from the field, the ability of a soil to hold water and nutrients will be greatly diminished. Therefore, growers should strive for both organic matter stabilization and mineralization processes to ensure short-term crop productivity and to build long-term soil resilience.
In 1987, a long-term cropping systems study started at the NDSU Carrington Research Extension Center. Three sets of 4-year crop rotations are replicated three times each year. The ninth cycle ended in 2016. This article will discuss some of the effects of using composted beef manure on soil properties and selected crop yields. Continue reading
Extension educators, crop consultants, and farmers working to improve soil health now have practical in the office or in the field resources. The new Iowa Soil Health Management Manual, Field Guide and a Soil Health Assessment Card are available at no cost.
The Iowa Soil Health Management Manual, Iowa Soil Health Field Guide, and Iowa Soil Health Assessment Card were recently published to increase understanding of soil health concept and their awareness of best management practices to protect soil health. These three publications are a collaborative effort between Iowa State University Extension and Outreach and the Natural Resources Conservation Service (NRCS), and can now be ordered or downloaded for free at the Extension Store.
The Soil Health Nexus was started with seed money from the North Central Region Water Network with representatives from 12 Land Grant Universities, Sustainable Agriculture Research and Education (SARE), Inter Tribal Ag Council, National Soil Health Partnership and the Natural Resource Conservation Service (NRCS). The purpose is to increase access to soil health research and resources available to extension staff, farmers, and their advisors who help them implement management practices that improve soil health on their farms.