Teaching Organic Farming and Gardening: Resources for Instructors, Part 1

471 Pages·2015·3.67 MB·English

UC Santa Cruz
Training Organic Farmers and Gardeners
Title
Teaching Organic Farming and Gardening: Resources for Instructors, 3rd Edition. Part 1 -
 Skills and Practices
Permalink
https://escholarship.org/uc/item/9k63s9c2
ISBN
978-0-9828781-0-1
Publication Date
2015-01-15

Peer reviewed
eScholarship.org Powered by the California Digital Library
University of California
PART 1
Organic Farming
and Gardening
Skills and
Practices
Unit 1.1:
Managing Soil Health 3
Unit 1.2:
Garden and Field Tillage and Cultivation 31
Unit 1.3:
Propagating Crops from Seed, and Greenhouse Management 95
Unit 1.4:
Transplanting and Direct Seeding 165
Unit 1.5:
Irrigation—Principles and Practices 203
Unit 1.6:
Selecting and Using Cover Crops 263
Unit 1.7:
Making and Using Compost 295
Unit 1.8:
Managing Arthropod Pests 341
Unit 1.9:
Managing Plant Pathogens 371
Unit 1.10:
Managing Weeds 393
Unit 1.11:
Reading and Interpreting Soil Test Reports 429

1.1
Managing Soil Health
Introduction 5
Lecture 1: Managing Soil Health— 7
Concepts, Goals, and Components
Lecture 2: Managing Soil Health— 13
Sustainable Agriculture Practices
Assessment Questions and Key 19
Resources 21
Supplements
1. A Soil Primer with Sustainable Management Strategies 25
2. The Global Socio-Environmental Effects of Soil Erosion 28
Part 1 – 4 | Unit 1.1
Managing Soil Health
Introduction: Managing Soil Health
UNIT OVERVIEW MODES OF INSTRUCTION
“Feed the soil to feed the plant” > LECTURE (2 LECTURES, 3 HOURS TOTAL)
is a basic principle of organic Lecture 1 presents the concepts, objectives, and compo-
nents of sound soil health and fertility management pro-
farming and gardening. This
grams for certified organic production systems.
unit introduces students to the
Lecture 2 describes the sustainable agriculture practices
ways that farmers and gardeners (e.g., tillage, cover crops, composts, soil amendments) that
develop and maintain soil health go into organic soil health and fertility management.
and fertility in organic farming > ASSESSMENT QUESTIONS (0.5 HOUR)
systems. Two lectures describe Assessment questions reinforce key unit concepts and skills.
the objectives and components of
LEARNING OBJECTIVES
soil health management and the
CONCEPTS
various practices used to develop
• Fundamentals of sustainable agriculture
and maintain healthy, fertile soil.
Supplements offer an overview of • Soil fertility in organic and sustainable farming systems
the soil ecosystem, and address • Soil quality
the way that sustainable soil • The relationship amongst soil fertility, plant health, and
management practices can combat the resistance and resilience of crop plants to pests and
pathogens
the environmental and social
• Goals of a sustainable fertility/soil management program
problems created by soil erosion.
Note that this unit introduces and • Components of a soil fertility management program
integrates a number of topics, • The role and impacts of tillage
including tillage and cultivation, • The role of cover crops in soil fertility management
composting, cover cropping, and
• The use of composts, manures, and other organic
irrigation, which are addressed in amendments
detail in subsequent units. • Nutrient budgets as a management tool
• Considerations in the design of crop rotations
It should be emphasized throughout the
lectures that the overall goal of a soil health
management program is to balance nutrient
inputs and outputs and ensure a good bal-
ance of nutrients for the crop. This balance
requires a complex mix of soil management
activities including proper tillage, irrigation,
crop residue management, weed manage-
ment, and crop rotation planning. Neglect-
ing any of these components can compro-
mise soil health and quality, affect crop
performance, and create potential pollution
problems due to erosion, nutrient runoff or
leaching.
Unit 1.1 | Part 1 – 5
Introduction Managing Soil Health
Part 1 – 6 | Unit 1.1
Managing Soil Health
Lecture 1: Managing Soil Health—Concepts,
Goals, & Components
Pre-Assessment Questions
1. What is organic farming?
2. If you were to implement an organic and sustainable soil fertility management program for
a farm or garden, what would be your overarching goals?
3. Then what would the main components of that fertility management program be?
4. How do you define soil quality?
5. How do you define soil fertility for an organic farming system?
6. How is soil quality related to pest management?
7. How is soil quality related to water management?
A. Sustainable and Organic Agriculture Defined
1. “Sustainable agriculture” defined
Sustainable agriculture can be defined as an approach to agriculture where the aim
is to create environmentally sound, economically viable, and socially just food and
agricultural systems. Emphasis is placed on renewable resources and the management
of self-regulating ecological and biological processes and interactions in order to provide
acceptable levels of crop, livestock, and human nutrition, protection from pests and
diseases, and an appropriate return to the human and other resources employed. Reliance
on external inputs, whether chemical or organic, is reduced as far as is practically possible.
The objective of long-term sustainability lies at the heart of organic farming and is one
of the major factors determining the acceptability of specific production practices. Note,
however, that certified organic agriculture also has a specific legal definition (see below).
Sustainable agriculture is not just the conservation of non-renewable resources (soil,
energy, and minerals) used to produce food and fiber. Sustainable agriculture also
encompasses: The maintenance or restoration of surrounding ecological landscapes; the
economic viability for all involved in agricultural production, processing and distribution;
and more equitable distribution of agricultural products to assure that basic human needs
are met (see Unit 3.4, Sustainable Agriculture and Sustainable Food Systems).
2. “Organic agriculture” defined
a) Organic agriculture has both general and legal definitions. Generally, organic agriculture
refers to farming systems that avoid use of synthetic pesticides and fertilizers. In the
United States, organic farming is defined by rules established by the U.S. Department of
Agriculture’s National Organic Standards Board (NOSB).
i. “Certified Organic” agriculture as defined by The National Organic Program (NOP;
www.ams.usda.gov/nop/)
Organic production: “A production system that is managed in accordance with the
Act (The Organic Foods Production Act [OFPA] of 1990, as amended in the NOP) to
respond to site-specific conditions by integrating cultural, biological, and mechanical
practices that foster cycling of resources, promote ecological balance, and conserve
biodiversity.”
Further, it is a system of agriculture that encourages healthy soil and crops through
such practices as nutrient and organic matter recycling, crop rotations, proper tillage,
and the strict avoidance of synthetic fertilizers and pesticides for at least three years
prior to certification
Unit 1.1 | Part 1 – 7
Lecture 1: Managing Soil Health—Concepts, Goals, & Components Managing Soil Health
b) Requirements for organic certification under the National Organic Program
i. Organic System Plan: The NOP requires that all crop, wild crop, livestock, and
handling operations requiring certification submit an organic system plan to their
certifying agent and, where applicable, the State organic program (SOP). The organic
system plan is a detailed description of how an operation will achieve, document,
and sustain compliance with all applicable provisions in the OFPA/NOP. The certifying
agent must concur that the proposed organic system plan fulfills the requirements.
The organic system plan is the forum through which the producer or handler and
certifying agent collaborate to define, on a site-specific basis, how to achieve and
document compliance with the requirements of organic certification. See the USDA’s
National Organic Program (NOP) website, www.ams.usda.gov/nop/ for additional
details of Organic System Plan requirements.
B. Soil Fertility and Soil Health in Sustainable Farming Systems
1. Soil health and fertility defined (see www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/,
and soilhealth.cals.cornell.edu/)
a) “Soil health” and “soil quality” can be used interchangeably. They are: The capacity of
a soil to function, within land use and ecosystem boundaries, to sustain biological
productivity, maintain environmental quality, and promote plant, animal, and human
health (Doran and Parkin 1994).
b) Soil fertility is a feature of soil health as applied to agroecosystems. It is the capacity of a
soil to provide nutrients required by plants for growth.
c) Soil health is established through the interactions of soil’s physical, chemical, and
biological, properties (see more at Supplement 1, A Soil Primer with Sustainable
Management Strategies, and Part 2, Applied Soil Science)
i. Physical properties include soil texture, a physical measurement of the percent of
sand, silt, and clay; and soil structure, the arrangement of individual soil particles
(sand, silt, clay) into aggregates or “clumps”
ii. Chemical properties of a soil measure its nutrient-carrying capacity and pH (acidity)
iii. Biological properties refer to the community of soil organisms (principally bacteria,
fungi, and actinomycetes)
d) Soil health indicators (see soilhealth.cals.cornell.edu/)
i. Soil provides adequate levels of macro- and micronutrients to plants and soil
microbes. This reflects the ability of the soil to mineralize nutrients and a moderate
pH (~6.0–7.0) that allows the nutrients to be both held in the soil and available to
plants as needed.
ii. Soil has good “tilth.” This includes a good structure that resists degradation (e.g.,
erosion and compaction), provides adequate aeration and rapid water infiltration,
and accepts, holds, and releases water to plants and groundwater.
iii. Soil promotes good root growth and maintains good biotic habitat that sustains high
and diverse populations of beneficial organisms and low populations of pests and
pathogens
iv. Soil has low salinity levels and low levels of potentially toxic elements (e.g., boron,
manganese, and aluminum)
v. Soil has high resilience and is able to withstand deleterious events, such as drought
and flooding
2. Soil fertility, plant health, and the resistance and resilience of crop plants to pest and
pathogens
a) Soil fertility requires a balance of critical plant nutrients. Either a deficiency or an excess
of nutrients can adversely affect plant growth, susceptibility to pests and pathogens,
and post-harvest quality.
Part 1 – 8 | Unit 1.1
Managing Soil Health Lecture 1: Managing Soil Health—Concepts, Goals, & Components
C. Goals of a Sustainable Soil Fertility Management Program
1. To sustain high crop productivity and crop quality in food and fiber production (not
maximum yields, which typically require excessive nutrient inputs to achieve)
a) Crop productivity, crop quality, and the economic viability of a given farming operation
2. To minimize environmental quality and human health risks associated with agricultural
production
a) Important steps in minimizing human health risks and on- and off-farm impacts
i. Avoid the use of all synthetically compounded materials (e.g., fertilizers and pest
control agents, etc.) known to have an associated environmental quality or human
health risk
ii. Avoid creating non-point source (NPS) pollution through surface runoff and leaching.
Excess nutrients (especially nitrogen and phosphorus) can degrade the quality of
groundwater, surface freshwater (e.g., rivers, lakes and wetlands), and nearshore
marine environments, causing eutrophication (low oxygen levels) and allowing
weedy species to outcompete native species as well as polluting drinking water
(see Supplement 5, Nitrate Contamination of Groundwater, in Unit 1.5, Irrigation—
Principles and Practices) among other negative effects.
iii. Prevent soil erosion and sedimentation of waterways. Soil loss reduces production
capacity and soil entering waterways may degrade aquatic habitat (see more at
Supplement 2, The Global Socio-Environmental Effects of Soil Erosion).
iv. Close nutrient cycles as much as possible within the field and farm to reduce energy
use and environmental impact of food and fiber production
v. Close nutrient cycles at multiple scales (e.g., watershed, regional, and national scales)
3. To assess and maintain soil health for long-term functioning of the above goals
D. Components of a Sustainable Soil Fertility Management Program: The Means to
Achieving the Above Goals
1. Improving and maintaining physical, chemical, and biological properties of soil involves
a suite of interrelated practices. Because these properties are so deeply and complexly
interconnected, soil health management requires an overall approach focused on how the
soil and plants are managed, rather than a product-based approach that focuses primarily
on delivering chemical “solutions” to nutrient and pest “problems.”
a) Sustainable agricultural practices used to improve and sustain soil physical and
biological properties
i. Maintain or increase soil organic matter (SOM) levels through inputs of compost and
cover cropping (see Unit 1.6, Selecting and Using Cover Crops and Unit 1.7, Making
and Using Compost). SOM has a high capacity to hold and release inorganic nitrogen
and other essential nutrients to plants. Organic matter inputs enhance the stability of
soil aggregates, increase the porosity and permeability to water and air, and improve
the water-holding capacity of soils. The primary constituents of SOM are organic
compounds rich in carbon. Building or maintaining the level of soil carbon provides
the energy and nutrients necessary to stimulate the soil microorganisms responsible
for decomposition and the formation of soil aggregates and more desirable soil
structure. See also: www.nature.com/scitable/knowledge/library/soil-carbon-
storage-84223790.
ii. Provide a balanced nutrient supply for the crop, also through compost and cover
cropping. Use in-season supplemental fertilizers (when suggested as necessary by
soil test results, plant growth observations, or plant tissue testing) to prevent or
address plant nutrient deficiencies. See the Cornell Soil Health Assessment Training
Manual for examples: soilhealth.cals.cornell.edu/.
Unit 1.1 | Part 1 – 9
Lecture 1: Managing Soil Health—Concepts, Goals, & Components Managing Soil Health