May 14, 2020Welcome, Soil, Soil Testing, and Peas! Frank Mangan,1 Heriberto Godoy-Hernandez,2 and Dawn Pettinelli3 To read individual sections of this article, click on the section headings below to expand the content: Introduction and Background Welcome to the first of a series of weekly articles with information on how to grow your own vegetables and herbs in Massachusetts for personal consumption. Given the situation with the Coronavirus disease (COVID-19), more people are staying at home and looking for fun activities they can do while maintaining social distancing and, of course, providing a source of healthy and nutritious food! These articles will be posted on the UMass Extension Home Lawn and Garden Resources website, with the goal of providing research-based information on how to grow specific vegetables and herbs appropriate for Massachusetts, and will be available in both English and Spanish. For some background, the University of Massachusetts, Amherst is the land-grant university for Massachusetts. Land grants were established in every state in the United States with legislation signed by Abraham Lincoln in 1863. The original name for what is now the University of Massachusetts, Amherst was the Massachusetts Agricultural College and its mandate was to provide instruction to Massachusetts citizens in "agricultural, mechanical, and military arts." The first class of 50 students was admitted in 1867. Now UMass Amherst has more than 30,000 students with 109 undergraduate, 77 master's and 48 doctoral programs. However, it still maintains its agricultural roots and provides research-based instruction to students in the agricultural sciences and to commercial farmers by faculty and staff in the Stockbridge School of Agriculture and the UMass Center for Food, Agriculture and the Environment, which includes UMass Extension and its programs in 4-H, Nutrition Education, Agriculture, Cranberries, Commercial Horticulture, Clean Energy, and Water Resources. Sources of Gardening Information An important source of information for growing vegetables and herbs in New England is the New England Vegetable Management Guide, which is available online at no charge. This guide is updated regularly by faculty and professionals with expertise on key aspects of sustainable vegetable and herb production at the six New England land-grant institutions.4 Other valuable sources of information for home gardeners in Massachusetts include: Massachusetts Master Gardener Association Western Mass. Master Gardener Association For Cape Cod Residents: Cape Cod Cooperative Extension Cape Cod Master Gardener Program All states in the U.S. and its territories have at least one land-grant institution which also provide research-based information on food production. If you are interested in growing vegetables or herbs in another state, contact the land-grant institution in that state for information more appropriate for the climate and growing conditions. Most run their own Master Gardener programs as well. Conventional and Organic Production of Vegetables and Herbs This is a large topic with a long history in the United States, including the creation of the Organic Foods Production Act of 1990. We will provide more information on recommended soil and pest management strategies for gardeners in subsequent articles, which will include both certified organic and conventional5 methods relevant to the home gardener. The Importance of Soil and Soil Testing for Growing Edible Crops Where To Start When Growing Your Own Vegetables And Herbs Outside: SOIL! Soil is the medium used overwhelmingly to grow food crops in New England, as opposed to the use of potting mixes or hydroponic systems. The soil is, among many things, an important medium for plant growth, from which plants take up essential water and nutrients for optimum growth.6 Vegetables benefit from “healthy” soils, which include optimum soil organic matter, nutrients and the appropriate soil pH for the species of plants being grown. The amount of organic matter—e.g. plant residues, composts, and manures—in soils varies dramatically. Higher organic matter means the soil can hold water better, has better drainage, and has higher activity of beneficial insects and microbes which feed on the organic matter.7 It can be challenging for commercial farmers to significantly increase the organic matter content of their fields since it would require applying large amounts of organic matter (e.g. manure, compost) that could be economically unsustainable, but in the home garden, applying organic materials such as compost and dried manure is fairly easy and economical. While applying organic matter can improve soil structure and function, and provide nutrients over many years, it can be easy to apply more organic matter than is recommended; too much organic matter in soils can provide more plant nutrients than needed and actually create toxic growing conditions. Using a base of topsoil and adding some organic matter is a good starting place. We’ll address this topic with subsequent articles. How do I know how much limestone, fertilizer and organic matter to add to my garden soil? Soil testing8 is key to determining what your present soil pH and nutrient levels are. It is an important and inexpensive tool to make sure your plants will be grown at the pH and nutrient levels needed for optimum growth and production. Tests for the amounts of organic matter in the soil may also be requested. No recommendations on organic matter additions are made in the test results, but generally a range of 4 to 8 percent for vegetable gardens is a good goal for most edible plants. Soil organic matter is an important source of nutrients and the levels of essential nutrients present are provided along with recommended amounts of nutrients to apply, which can be seen on the soil test results. Nitrogen is not included in routine soil testing because it varies widely depending on environmental conditions. Instead, nitrogen recommendations are based on past field studies of various crops. In general, the higher the soil organic matter, the less nitrogen fertility is needed. Soils with organic matter above 8% normally do not need the addition of nitrogen fertilizers for vegetable production. Soil test results indicate the soil pH, major plant nutrients, trace elements, a lead scan and include limestone and fertilizer recommendations. Interpretation sheets explaining in more detail accompany soil test results. Another important reason for soil testing is to check for the presence of lead. How do I collect a soil sample? First, determine how many samples you would like to send in. If just for a new garden plot, one composite sample would be sufficient. More than one sample might be sent in for testing if different areas of the garden have received different amounts of limestone and fertilizer, or different sections of the property are used for different purposes. For instance, one would send in separate samples for an old amended vegetable garden and a new, not yet amended, garden site, or separate samples for the vegetable garden and the lawn. If additions of compost or manure are planned, add an inch or so to the garden bed and incorporate it into the top 4 to 6 inches of soil. Wait 2 to 3 weeks and then collect and send in a soil sample. Often the nutrients added by compost and manure make additional fertilization, and sometimes adding lime, unnecessary. Each soil lab has its own instructions for the preparation of samples, required information and labeling, and payment. See https://ag.umass.edu/soil-plant-nutrient-testing-laboratory/fact-sheets/sampling-instructions-for-routine-soil-analysis for the UMassSoil and Plant Nutrient Testing Lab and http://www.soiltest.uconn.edu/documents/Newsoilsampinstructforhomelawnldscp.pdf for sampling for the UConn Soil Nutrient Analysis Lab. Lead in Garden Soil Lead is a naturally occurring element and soil background levels may be in the range of 15 to 40 parts per million (ppm). Higher levels are frequently found in New England soils due to lead paint from buildings, leaded gasoline emissions, and the past use of lead arsenate as a pesticide in orchards. Lead poses human health risks, especially to children, affecting their neurological development. Childhood lead poisoning still remains a very serious health threat in this country. Because children partake of so many hands-to-mouth activities, they are at a high risk of exposure to lead that has accumulated in the soil through human activities. Both the UMass and UConn soil testing labs include a lead screening with their standard nutrient analyses. Do note that both the UMass and UConn test results measure extractable, or “plant-available” lead as opposed to total lead, using the same extractant (Modified Morgan) as is used for the other elements of interest. The UConn lab test results also include the Total Estimated Lead level of the soil. While this approach provides a low cost method for making both fertilizer recommendations and basic screening for lead level risk, accurate determination of lead levels requires a Total Sorbed Metals test, such as that offered by the UMass Soil Testing Lab. Consider testing your soil for lead if you live in a house built before 1977, your garden plot is near a heavily traveled, older roadway or near an old painted structure (former or present), you live in an urban area where manufacturing is or was present, or on an old agricultural site where lead arsenate pesticides could have been used. If elevated levels are found, appropriate interpretation sheets will be sent with your results. Vegetable/Herb of the Week: Peas (Pisum sativum) Modified from the New England Vegetable Management Guide Peas (Pisum sativum) belong to the legume family and are a cool season crop that may be planted as early in the spring as the soil has thawed. Peas originated in the Mediterranean and Near East, were eventually domesticated throughout Eurasia, and were then brought to the Americas by immigration from Eurasia. Field peas are commonly grown as a cover crop, or, in more arid regions, for its smooth dried seeds used as food or animal feed. Garden pea is more commonly grown in New England for fresh eating, and you may also know them as sweet pea, sugar snap peas and snow peas. Garden peas contain higher sugar and lower starch contents than field peas. Plants in the legume family, including peas, can form a symbiotic relationship inside their roots with certain species of bacteria (Rhizobia species) that turn nitrogen from the atmosphere (which is 78% nitrogen) into forms of nitrogen that the pea plant can take up and use to grow, while the plant in turn provides sugars for the bacteria. While some legumes need to be inoculated with the right species of Rhizobia bacteria, garden peas are relatively short-lived and therefore can usually get all the nitrogen they need from the soil or fertilizers. By the time the bacteria are able to provide significant nitrogen, the peas would be dying off. There are three types of garden peas grown in Massachusetts, all of which come in dwarf and tall, climbing forms: English/Shelling – only the seed is eaten Snow or Edible-Podded – the pod is eaten with undeveloped seeds Sugar or Sugar Snap – both pod and seed are eaten For all vegetables and herbs listed in the New England Vegetable Management Guide, recommendations for specific varieties appropriate for production in New England are listed. These recommendations are provided by commercial farmers and Extension staff across New England. Note: Here is an interactive Massachusetts farm locator produced by the Massachusetts Department of Agricultural Resources which lists of 14 different categories of farms in Massachusetts where you can find sources for seeds, transplants, and fertilizers, among other supplies related to growing your own vegetables and herbs. The range of what gardening supplies each operation will have can vary, so it's best to call first. Table 1. Pea varieties recommended for New England* English/Shelling Pea Snow Pea Sugar Snap Pea Strike (49**) Oregon Giant (60) Sugar Ann (52) Premium (51) Avalanche (60) Sugar Spring (58) Penelope (51) Blizzard (61) Sugar Snap (62) Knight (62) Oregon Sugar Pod 2 (65) Super Sugar Snap (66) Progress #9 (62) Maxigolt (62) Green Arrow (65) Lincoln (67) Wando (68) *Taken from the New England Vegetable Management Guide. **The number in parentheses is the approximate number of days to maturity from seeding. It is recommended to stake or trellis peas, which will provide better growth and easier harvest. I use what are called in the industry “tomato stakes”, since they are commonly used with tomato production. I seeded peas in my garden in central Massachusetts on April 12 this year (2020). The variety I used was “Premium," #2669, untreated, from Johnny’s Selected Seeds. It is an English/Shelling pea and one of the varieties recommended in Table 1. Figure 1. Frank Mangan’s home garden on April 24, 2020 with a bed on the right planted with peas on April 12. It is recommended to set up whatever trellising system you’ll use right after seeding so you’re ready to go when thepeas come up. (Photo by Frank Mangan) References 1 Extension Professor of Vegetable Crops, Stockbridge School of Agriculture, UMass Amherst. 2 PhD student of Vegetable Crops, Stockbridge School of Agriculture, UMass Amherst. 3 Dawn Pettinelli, Associate Extension Educator, Department of Plant Science & Landscape Architecture, UConn Soil Nutrient Analysis lab, University of Connecticut. 4 University of Massachusetts, Amherst; University of Vermont;University of New Hampshire; University of Maine; University of Connecticut; and the University of Rhode Island. 5 The term “conventional” is used for non-certified organic production of food. 6 See “Soil and Plant Nutrition: A Gardener’s Perspective," by Dr. Lois Berg Stack and Mark Hutchinson (2016). 7 For more information on this subject, see Building Soils for Better Crops, 3rd Edition, which is available at no charge. This book had a huge impact on my thinking on agricultural soils and I have used it as a required textbook when teaching a third-year 4-credit course on Vegetable Production. 8 Due to the Coronavirus outbreak, the UMass Soil & Plant Nutrient Testing Lab is closed as of this writing (5/14/20) and unable to accept samples, but the University of Connecticut Soil Nutrient Analysis Laboratory offers the same analysis and is accepting samples for analysis.