DDR is a digital repository maintained by the USDA National Agricultural Library that preserves and makes accessible research and information on agriculture, food, and the natural resources. Here you can find USDA authored full-text articles, books, book chapters, conference papers, images, and more, on a wide range of topics.
To search all of DDR, use the search box at the top of the navigation bar on the left (or the search box in the middle of the home page)
To limit your search to a specific community or collection, navigate to that community or collection and use the search bar on that page.
Here are some search hints:
What is searched in the general keyword search? The word(s) you enter in the search box will be searched against the title, author, subject, abstract, and identifier fields of each item's record, and the full-text of the document if available.
What is not searched - Stop Words Certain words that occur frequently in English, but do not add value to the search, are ignored. These are:
Truncation Use an asterisk (*) after a word stem to get all hits having words starting with that root, for example:
will retrieve selects, selector, selectman, selecting.
Stemming The search engine automatically expands words with common endings to include plurals, past tenses ...etc.
Phrase Searching To search using multiple words as a phrase, put quotation marks (") around the phrase.
Exact word match Put a plus (+) sign before a word if it MUST appear in the search result. For instance, in the following search the word "training" is optional, but the word "dog" must be in the result.
Eliminate items with unwanted words Put a minus (-) sign before a word if it should not appear in the search results. Alternatively, you can use NOT. This can limit your search to eliminate unwanted hits. For instance, in the search
or
you will get items containing the word "training", except those that also contain the word "cat".
Boolean searching
The following Boolean operators can be used to combine terms. Note that they must be CAPITALIZED !
AND - to limit searches to find items containing all words or phrases combined with this operator, e.g.
will retrieve all items that contain BOTH the words "cats" and "dogs".
OR - to enlarge searches to find items containing any of the words or phrases surrounding this operator
will retrieve all items that contain EITHER the words "cats" or "dogs".
NOT - to exclude items containing the word following this operator, e.g.
will retrieve all items that contain the word "training" EXCEPT those also containing the word "cat".
Parentheses can be used in the search query to group search terms into sets, and operators can then be applied to the whole set, e.g.
The advanced search page allows you to specify the fields you wish to search, and to combine these searches with the Boolean "AND", "OR" or "NOT".
Select the field to search in the left hand column and enter the word or phrase you are searching in the right hand column. Select the Boolean operator to combine searches by clicking on the arrow to the right of the "AND" box.
Note: You must use the input boxes in order. If you leave the first one blank your search will not work.
The following fields can be searched:
Keyword: search for words in the title, author/creator, subject, and identifier fields, and words in the abstract/summary and/or fulltext document if available.
Author: words in the author and creator fields only.
Title: words in the title only.
Subject: words in the "NALT Subjects" and "Other Subjects" fields only.
Note: NALT Subjects are vocabulary terms provided by NAL indexers from NAL’s Agricultural Thesaurus (NALT) that help to systematically describe a document. These terms can be used by the searcher to help locate relevant material. The thesaurus is available online at http://agclass.nal.usda.gov/agt/agt.shtml.
Other Subjects are terms applied by NAL indexers that provide additional description.
Abstract: words in the abstract/summary only.
Note: Not all documents in DDR contain an abstract/summary.
Identifier: words in the Identifier field only. This field contains a unique document number from the 016 field of NAL’s Agricola Online Catalog and Article Citation Database at http://agricola.nal.usda.gov.
Language: words in the Language field only.
Note: DDR currently contains English language documents only.
VIEW AN ITEM (Document, Image, Presentation, etc.)
To open and view a document in DDR navigate to the item’s record via a browse or search. At the top and bottom of the record you will see the following dialog box displayed:
Select the "View/Open" link to access the document. Once the document is displayed you will be able to Save/Print from your computer.
To view PDF files you must have Adobe Acrobat Reader installed on your computer. Files in other electronic formats may require additional software.
Every document in DDR is assigned a permanent URL, meaning that unlike most URLs it will never change. Thus, you can reliably cite and provide access to documents in DDR knowing that the link will always work. DDR uses the Handle System to maintain these persistent links. The URL for an DDR document can be found at the top of the document’s record and in the URI field of the record. It will have the form of http://hdl.handle.net/10113/58. Use this URL when citing and providing access to an DDR document in, for example, a bibliography or reference note.
Users can subscribe to receive daily e-mail alerts of new items added to collections. Users may subscribe to as many collections as they wish. To subscribe:
go to the "Login to DDR" page by clicking on the "Receive E-mail/Updates" link in the navigation bar on the left ofthe home page, or go to the collection homepage you want to receive alerts for and select the "Subscribe" button.
if you are a new user, select the "New User, Click Here to Register" link and provide your email address. You will immediately be sent an email with a link to a registration form. Open the form and fill-in the required fields to complete the registration.
navigate to a collection for which you would like to receive e-mail alerts, and click on the "subscribe" button (repeat for other collections)
to edit your subscriptions, go to the "Subscribe" page.