Soil aeration and crop growth in response to excess water

The general purpose of this study was to monitor the soil aeration status during flooded and unflooded conditions over the corn growing season, and to determine corn growth response to artificial flooding on both isolated field plots (specially constructed for controlling water-table elevations) and plots that drained naturally;To sample and analyze the soil atmosphere for oxygen (O[subscript]2) concentration, a new technique was developed and tested in laboratory columns and field plots. Laboratory testing showed that the new sampling technique was fast, reliable, and free of outside air contamination during sampling and analysis;Artificial flooding of soil reduced O[subscript]2 concentrations, redox potentials (Ehs), and oxygen diffusion rates (ODRs) below the critical levels at all the sampling depths resulting in inadequate soil aeration and restricted supply of O[subscript]2 to plant roots. High water tables occurring in plots with natural drainage, due to flooding of an adjacent isolated field plot, and increased wetness on the soil surface of all the experimental plots as a result of heavy rains, also caused a decrease in the values of these three aeration indicators used in this study. The relationships between the air-filled pore spaces in soil and the three aeration indicators suggested that an aeration porosity of 8 to 10% was necessary to have adequate aeration for good plant growth;Flooding corn at the early (36 days after planting), and the late (56 days after planting) vegetative stages resulted in poor crop growth (plant-canopy height and dry-matter production) and reduced grain yield. These two vegetative stages of corn growth, also gave the highest crop susceptibility (CS), and normalized crop susceptibility (NCS) factors for corn for the 1987 and 1988 growing seasons;The relationships between the stress-day index (SDI) and the relative yields of corn grown at the experimental site and a nearby undrained area indicated a linear decrease in relative yields with increasing soil wetness (SDIs)

Using Compost for Erosion Control and Revegetation

Composting refers to the biological decomposition and stabilization of organic materials by microorganisms under aerobic conditions. Compost from various materials (yard trimmings, manure, food processing residuals and other organic materials) has been used to improve soil quality and productivity and prevent soil erosion. This publication explains how compost can be used for those purposes

Manure to Energy: Understanding Processes, Principles and Jargon

4 pp., 2 illustrationsThe increasing demand for energy and the high costs of oil and natural gas have emphasized the need for consumers to seek alternative energy resources. This publication explains the processes for converting manure to energy

A Review of Practices and Technologies for Odor Control in Swine Production Facilities

The objective of this article is to provide a systematic review on practices and technologies for odor control in swine production facilities and to summarize available data on odor reduction effectiveness of promising technologies, as well as provide information on key parameters and associated costs. Odors from swine facilities comprise hundreds of chemicals, including volatile organic compounds (VOC), ammonia (NH₃), and hydrogen sulfide (H₂S). The medians of emission rates from swine houses in literature are 5 OU/s/pig for odor, and 0.4, 2.8, and 0.1 kg/yr/pig for VOC, NH₃, and H₂S respectively. The medians of emission rates from swine manure storage facilities in literature are 5 OU/s/m2 for odor, and 1.4, 2.1, and 0.2 kg/yr/pig for VOC, NH₃, and H₂S, respectively. Facility maintenance and management practices to reduce impact of odor are reviewed in regard to regular cleaning of facilities, ventilation, floor design, drainage and manure removal systems, frequent manure removal, manure storage, and odor separation distances. Approaches to control odor and air pollution can be classified into three categories: ration/diet modification, manure treatment, capture/treatment of emitted gases and enhanced dispersion. Each of these mitigation approaches includes several specific technologies, which are summarized in tables with an evaluation of overall cost and brief comments on advantages or limitations of each technology. Diet modification strategies have been shown to reduce NH₃ emissions effectively with low cost and should be considered as a best management practices, although their effectiveness in reducing odor is still uncertain. Permeable covers and biofilters seem to have great potential to be the most promising and cost effective technologies for manure storage facilities and swine houses respectively. However, both of the technologies need careful maintenance to perform effectively. Care must be taken to select technologies that are compatible with the management capabilities of the operation to prevent potential failure due to mismanagement

Effect of Short-term Flooding and Drainage on Soil Oxygenation

Three aeration indicators, namely oxygen (O2) concentration, redox potential (Eh), and oxygen diffusion rate (ODR), were measured to determine the aeration status of soil under short-term flooding and unflooded conditions. Relationships between these indicators were developed and results of some measurements made over short time intervals during flooding and drainage of soil are presented

Remodeling Existing Structures

Marty grew up in Wellman, Iowa, on his great uncle\u27s hog farm. He purchased a portable nursery, and he uses lean-to\u27s and a shed as breeding areas. His uncle sold the sows after he got started. Now he weans the pigs and takes them to this uncle\u27s site. Vern worked in Extension for approximately 35 years. He became interested in swine development in the late 1960s, and has a number of ideas on renovation (see handout at the end of this section). His philosophy is that if both the foundation and the roof of a structure are bad, one should try to use it as it is or tear it down. Jim has a farrowing house, converted cattle sheds, and the like. The farrowing house originally was a nursery, then additions were done to divide it into rooms and pens, so the nursery will hold 475 head. Insulation keeps the heat in for the nursery and the sow rooms, but the walls sweat

Engaging in Conversations about Climate Change with Cattle Producers

The purpose of this study was to determine whether Cooperative Extension Service agents and United States Department of Agriculture Natural Resources Conservation Service (NRCS) personnel used a dialogic model of communication in their interactions with cattle producers in the Southwest and Mountain West regarding the topic of climate change. Findings indicated that dialogic communication is being used, with a focus on discussing best management practices, avoiding the term “climate change,” and focusing on local data and weather events. The study suggests that Extension agents and NRCS personnel recognize the need to adapt their communication strategy and tactics to suit the cognitive needs and beliefs of the cattle producers with whom they converse. Additionally, findings suggest that climate change should be described in terms that are observable to cattle producers, such as weather events (drought or flooding), possibly minimizing the need to name such events as climate change

Excessive Soil Water Effects at Various Stages of Development on the Growth and Yield of Corn

The response of corn to naturally fluctuating water tables at five different stages of growth was studied for 3 years. Fifty plots of 15 m x 15 m were established in 1984 on Nicollet soil in an area that is not artificially drained. In the center of each plot, an observation well was installed for water-table measurements. Water-table hydrographs were developed for each plot annually to quantify crop stress factors from excessive wetness (SEW30, a summation of days times the height of the water table above 30 cm). The results of these studies indicate that SEW30 values of as low as 40 cm-days in the early part of the growing season can significantly reduce corn yields. Corn yields decreased linearly with the increase in SEW30 values and the Stress Day Index (SDI). Lower corn yields resulted from both decreased plant population and poor crop growth due to excessive wetness