Archive | Weeds

Natural Weed Control

There are many ways for growers to implement non-toxic weed control methods on their farms. The most obvious is to take the chemical farming approach and find an organically-approved material to do the killing. Very strong vinegar has been the most marketed material. The important factor in vinegar formulas is to include a surfactant to strip away any waxy protective coating on the plant surface to allow the desiccation (drying out) of the plant. Salt provides the same mode of action and may be included in the formula.

Natural weed control

The primary condition that promotes broadleaf weeds is the ratio of available phosphorus to available potassium, as shown by a LaMotte soil test. The further you deviate from a 1:1 ratio, the stronger the broadleaf pressure.

Other modern mechanical approaches to weed control include flaming, cultivating, and smothering. Cultivators are a modern version of hoeing or hand pulling. Rotary hoes or spiked harrows are special adaptations of the cultivation approach. Using plastic films, whether biodegradable or not, is a form of smothering that is similar to mulching with any material. The cover denies sunlight to prevent growth.

Repeated cuttings of a perennial weed in a fallow field may weaken a plant over time by using up its stored energy. Farmers should also make every attempt to prevent the reseeding of an offending species. Treating isolated patches is worth the effort to keep them from spreading. If a field is overwhelmed to a point of not having an economic crop worth harvesting, be sure to take the whole field down before the weeds go to seed. Keep in mind that there are seeds in your fields that may have been there for years. Just lime or activate the calcium in your soil and watch clover appear in uncultivated ground, even if you haven’t seeded it since you bought the farm.

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Homemade Fertilizers

With the economy and farm finance more and more problematic, interest is growing in running farms with fewer, more accurate and less expensive inputs and homemade fertilizers can help cut costs and keep fertility on the farm.

homemade fertilizer

Vermiwash made in a small biodynamic apple orchard in the
Himalayan foothills of Uttaranchal in sight of Nanda Devi, India’s second highest

Formerly we’ve overdosed with a plethora of harsh fertilizers — especially nitrogen. As a result we’ve burned up the better part of our soil carbon, and this has reduced our rainfall.

By burning off carbon, we have created droughts even as ocean warming has sent more evaporation into the atmosphere. We have ignored that few things have more affinity for hydrogen than carbon, and if we want rain to adhere to and permeate our soils we need to build soil carbon.

We thought salt fertilizers were cheap, and the stunning results encouraged us to wish away any hidden costs, no matter that earthworms disappeared simultaneously with the food chain that supported them. Our soils got hard and sticky as magnesium stayed behind while nitrates leached, carrying away silicon, calcium and trace minerals. The soil fused when wet, shed water when it rained, and we continued to get less for more.

As if this wasn’t enough, the mind-set we were sold was get big or get out. As our net margins dried up and our future prospects evaporated, our water dried up and our land became exhausted. Continue Reading →

Soil Restoration: 5 Core Principles

Soil restoration is the process of improving the structure, microbial life, nutrient density, and overall carbon levels of soil. Many human endeavors – conventional farming chief among them – have depleted the Earth to the extent that nutrient levels in almost every kind of food have fallen by between 10 and 100 percent in the past 70 years. Soil quality can improve dramatically, though, when farmers and gardeners maintain constant ground cover, increase microbe populations, encourage biological diversity, reduce the use of agricultural chemicals, and avoid tillage.

Soil restoration begins with photosynthesis.

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Soil Testing: The Need for Total Testing

What many farmers probably don’t know about soil testing is that most soil tests only tell us what is soluble in the soil. They do not tell us what is actually there in the soil, no matter what fertilizer salesmen might like to imply. To find out what is actually there requires a total acid digest similar to what is used for plant tissue analysis. Mining labs run these total acid di­gests on ore samples which are crushed, ground and extracted with concentrated nitric and hydrochloric acid solutions, but a mining assay does not determine total carbon, nitrogen and sulfur as a plant tissue analysis would. These ele­ments need a separate procedure essen­tial for evaluating soil humic reserves.

Total soil testing is key to understanding your soils’ needs.

Most soil tests measure total carbon, which then is multiplied by 1.72 to calcu­late soil organic matter. This assumes that most of the carbon in the soil is humus of one form or another. While this may or may not be true, determining the car­bon to nitrogen, nitrogen to sulfur, and nitrogen to phosphorus ratios is a good guide for evaluating organic matter, and this requires testing total nitrogen, sulfur and phosphorus as well as carbon.

While carbon in almost any form is a benefit to the soil, it helps enormously if it is accompanied by the right ratios of ni­trogen, sulfur and phosphorus. Though these ratios are not set in stone, a target for carbon to nitrogen is 10:1, for nitro­gen to sulfur is 5.5:1 and for nitrogen to phosphorus is 4:1. This works out to an ideal carbon to sulfur ratio of 55:1, and a carbon to phosphorus ratio of 40:1. Because soil biology is very adjustable these targets are not exact, but achieving them in soil total tests is a good indica­tion of humus reserves that will supply the required amounts of amino acids, sulfates and phosphates whenever the soil food web draws on them. Continue Reading →

Cover Crops on the Farm

Cover crops are increasingly being used by farmers across the country to suppress weeds, conserve soil, protect water quality and control pests and diseases.

cover crops on the farm

A mix of rye, clover and vetch. Farmers have steadily increased their use of cover crops over the past five years.

The fourth annual SARE/CTIC Cover Crop Survey collected data from more than 2,000 growers from 48 states and the District of Columbia. The survey provides insight into cover crop usage and benefits and explores what motivates farmers to include cover crops in their farm management and soil health plans.

Respondents reported a steady increase in the number of acres they have cover cropped over the past five years. They said the most important benefits of cover crops include improved soil health, reduced erosion and compaction, and increased soil organic matter. Other reported key benefits of using covers are weed and insect control, nitrogen fixation, attracting pollinators and providing deep taproots.

North Central SARE (Sustainable Agriculture Research and Education) and CTIC (Conservation Technology Information Center) sought data on how farmers use cover crops to manage their fertilizer inputs. Growers were asked to indicate their level of agreement with a series of fertilizer-related statements using a scale ranging from 1 (strongly agree) to 5 (strongly disagree). The statement that got the highest level of agreement was “Using cover crops has enabled me to reduce application of nitrogen on my cash crop,” with 134 of 1,012 respondents strongly agreeing and 244 checking “agree.” The statement that had the highest level of disagreement was “Using cover crops has required me to use additional crop fertility inputs over time to meet the needs of my cash crop.”

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Flame Weeding: Turn up the Heat to Fight Weeds

Flame weeding (also referred to as flaming) has been an apt option for or­ganically ridding row crops and fields of uninvited weeds while also replenishing the soil with nutrients from the result­ing carbon. Wedding the proficiency of flame with the compressed liquid power of propane has served many farmers and food producers well over the past cen­tury. According to the Northwest Coalition for Alternatives to Pesticide, the first agricultural flame weeder was patented in 1852.

flame weeding with propane

Flaming with propane attacks weeds with no repercussions on crops or fields.

Flame weeding is done by generat­ing intense heat through a chosen de­vice — whether it is a handheld torch or tractor-mounted — that sears the leaves of the weeds, which causes the cell sap to expand, thusly damaging the cell walls. “You’re watching for the color change, depending on the weed and its maturity,” said Charles House of Earth & Sky Solutions. Leaves wilt and dehydrate the plant, leaving the invaders no other option than to die, sometimes up to three days later.

“The key to successful flame weeding is the maturity of the plant you’re trying to eradicate. The smaller, the better,” he explains. The best time is when they’re immature and in the cotyledon stage.

Flame Weeding Background

Flaming gained popularity in the first third of the 20th century and continued through the 1960s until pesticides re­placed industry attentions. Though its use waned over the following 20 years, flame weeding resurfaced and regained popularity in the early 1990s, and con­tinues to be used today. So continues flame weeding’s renaissance. Continue Reading →