Ag Connection
Your link to the Universities for ag extension and research information

Volume 7, Number 12
December  2001


This Month in Ag Connection

Grain Storage Management

Remember to manage grain stored on your farm. This was addressed in the September 1998 Ag Connections newsletter.

More information is available on the Missouri Grain Storage web site.

These articles may also be obtained at your local University Outreach and Extension office.

(Author: Don Day, Ag. Eng./Info. Tech. Spec., University Outreach and Extension)



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Black Walnut Husks -- No Threat to Forage Production

Millions of pounds of black walnuts are harvested each year and the husks are removed before weighing, leaving large piles of residue. Walnut husks contain allelopathic compounds (substances that hinder plant growth) that can cause environmental problems if they leach out. These agents are a natural herbicide. Typically, these large piles of waste husks have been left at the walnut buying/hulling stations or hauled off and dumped.

University of Missouri Center for Agroforestry research found that spreading hulls on forage crops is an environmentally sound way to dispose of this waste. There is also a benefit of increased forage growth.

Initial trials used orchardgrass with three levels of walnut husk applications: at zero, 15 and 30 tons per acre. The results suggested that allelopathic activity was not a major factor when husks were applied at these rates.

Later field trials were held at the MU Horticultural and Agroforestry Research Center in New Franklin, Mo. Red clover was treated with zero, 15 and 30 tons of walnut husks per acre. The 30 tons of walnut husks per acre gave the highest yield. The best results for orchardgrass were observed at 15 tons-per-acre.

The researchers said, “husks from black walnut hulling stations can be safely applied to orchardgrass and red clover. Negative growth responses from the application of husks to other forage species is not expected, although these species have not been tested.” While application rates up to 30 tons per acre were tested, the optimum application rate would appear to be between 15 and 30 tons per acre. Based on studies with juice from fresh green husks, we would not recommend spreading them if there is a threat of rain within twelve hours. You may request the entire report from you local University Outreach and Extension Center or click here to view it on the web.

(Source for this article is Gene Garrett, Director of the University of Missouri Center for Agroforestry -- 573/882-3647)

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Handheld GPS Receivers for Agricultural Uses

In 2001 the University of Missouri began a series of projects to determine if the recreational, handheld Global Positioning System (GPS) receivers costing less than $300 could be used to replace Differential GPS (DGPS) receivers costing more than $2000 for applications in crop scouting and creating crop yield maps. The study found the average relative difference between a DGPS system and handheld GPS receiver was less than 6 feet. Therefore GPS units normally marketed toward recreational uses can be used for agriculture for crop scouting, grid soil sampling and yield mapping.

GPS receivers use the method of triangulation to measure the latitude and longitude of where the GPS unit is located based on radio signals it receives from a constellation of satellites. All together there are 24 active U.S. deployed GPS satellites with as may as half of these transmitting their radio signal across the horizon at any given time. In order to calculate its position a GPS receiver must receive a signal from a minimum of three satellites. WAAS, DGPS and RTK GPS receivers use additional radio signals from satellites and/or ground-based towers to more accurately calculate their positions. Applications of this information includes mapping field boundaries, pest problems, terraces, waterways, buried tile line, etc., and to make crop input maps as well as crop yield maps.

Differential correction was required to achieve an accurate position due to the dithering (a random mathematical error) of the raw GPS satellite signal imposed by the U.S. Department of Defense. However in May 2000, the GPS satellite signal was no longer dithered or altered in any way unless determined necessary for national security reasons. With this occurrence, non-corrected 12 channel GPS receivers that originally achieved a position accuracy of 150 feet are now accurate to about 20 feet. Considering that most modern farm implements have a width that is greater than the accuracy of the non-corrected GPS receiver, several Universities began research projects to determine if these lower cost GPS receivers can be used but not totally replace DGPS.

Before purchasing and using a lower cost GPS receiver, farmers should be aware of the following:

Handheld GPS receivers rely on batteries as their source of power. On most models, batteries should provide 10 – 24 hours of use. Some models have an optional 12 V DC power cord adaptor.

If the GPS receiver is to be used with a yield monitor or other field computer, it must have the ability to attach an output cable and be able to transmit data in a standard NEMA output string.

When using handheld GPS receivers with a yield monitor, it is necessary to mount the GPS receiver on the outside of the tractor or combine. Interference within cabs created a higher level of inaccuracy with the GPS receiver.

University of Missouri staff were able to connect handheld GPS receivers manufactured by Garmin to yield monitors manufactured by AgLeader , MicroTraK, GreenStar and Case AFS. (It is believed that other brands of GPS receivers can also be connected to these yield monitors.)

It is recommended that farmers use a DGPS system for recording field boundaries, measuring yield trials, measuring on-farm research plots, recording survey flag locations and other occurrences where location position accuracy is required to be less than 3 feet. Since these points and areas do not change throughout the cropping season, a farmer may choose to hire a consultant to record this information and purchase a lower cost GPS receiver for other application that do not require an accuracy of less than 6 feet.

(Author: Darin Starr, University Outreach and Extension Ag. Engineering Spec.)

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Personal Data Assistants for the Farm

When Personal Data Assistants (PDAs) first appeared in the public market, they were used only to keeping appointment calendars, clientele contact information, and job task lists. Later these devices were designed to run word processing and spreadsheet software programs. This same computer tool that found its initial home on Wall Street is showing up on farms.

PDAs are a companion tool to today’s desktop computer, allowing the user to carry a handheld device to collect and record information on the go. The information can then be downloaded to the desktop computer without re-entering. Companies that design software for farming applications are starting to develop “companion” versions for the PDA.

In addition to software applications, PDAs have a wide variety of options that can be useful to the farm manager. They may include:

Built in voice recorder that can record up to 3 hours of audio.

Built in expansion slots that allow for additional memory as well as plug-in digital camera.

GPS antennas.

Antennas for wireless Internet connections (wireless Internet is available only in limited geographic locations and requires a service subscription).

When purchasing a PDA here are some things to consider:

Data entry – PDAs offer two methods of data entry: touch screen or a built in mini keyboard. Most new PDAs are exclusively using the touch screen for data entry and offer a portable, expandable keyboard only as a optional accessory.

Operating system - The two most popular operating systems for PDAs are Palm OS and Windows CE. Be sure the PDA purchased uses the operating system required by the software you want to run. For example, FarmWorks TM software requires a Windows CE operating system while PigWIN TM requires Palm OS.

Battery life – The battery life of PDAs varies greatly between models. Most batteries are internal with no way to change old batteries for new ones. An AC recharging adaptor as standard equipment is used to recharge the unit’s power. Most offer a DC recharging/ power adaptor that allows the PDA’s batteries to be recharged by plugging the unit into a vehicle’s cigarette lighter/auxiliary power outlet.

Warranty - Working in an agriculture setting could expose your PDA to dust, moisture, cold temperatures and the occasional dropping the unit on a concrete floor or muddy ground. Each of these conditions will adversely affect the performance of your PDA and can cause it to stop functioning. Be sure to check what the warranty covers as well as how long the warranty lasts. For harsh environments, a ruggedized PDA may be needed.

Accessories available – There are many accessories on the market today for PDA’s. Unfortunately most accessories can only be used with specific PDA models. If you think you are going to use a specific external or plug-in accessory (camera, GPS receiver, etc), be sure to buy the PDA that lists those items as available.

Included software – All PDA’s come with some software installed: calendar, contacts, task list, notepad, etc.

Memory – PDAs come with anywhere from 8 Mb – 128 Mb of memory. If you will be adding software to your PDA, using it as a digital camera, or recording a lot of audio, purchase more memory. Almost all PDAs will allow you to expand memory at a future date; however, this will take up the PDA’s expansion slot and limit the use of other accessory you may want to use.

(Author: Darin Starr, University Outreach and Extension Ag. Engineering Spec.)

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Taxation Tidbits:  Treasury & IRS Encourages Year-End Capital Expenditures 

The Treasury Department and the IRS intend to issue regulations permitting taxpayers to elect not to apply the mid-quarter depreciation convention rules if the 3rd quarter of the taxpayer’s 2001 taxable year includes September 11, 2001. Normally, mid-quarter instead of half-year depreciation convention is required for current year purchases - if the aggregate basis of property placed in service during the last three months of the taxable year exceeds 40 percent of the aggregate basis of property placed in service during the entire taxable year. Notice 2001-70, 2001-45 IRB 437 has been issued to provide taxpayers a mechanism for making the election before the regulations are issued.

To make this election, taxpayers must place “Election Pursuant to Notice 2001-70” across the top of their Form 4562, Depreciation and Amortization.

(Author: Parman R. Green, University Outreach and Extension Farm Business Management Specialist)

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University Outreach and ExtensionAg Connection - Ag Connection Newsletter,  December 2001 -- Revised: September 30, 2002