In This Section |
Horticultural Crops
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| Author: | OMAFRA Staff |
|---|---|
| Creation Date: | 19 July 2002 |
| Last Reviewed: | 04 May 2004 |
Horticultural crop growers share many of the same management concerns of other producers. Although horticultural crops vary substantially, they all require skilled management to produce a high quality product. These crops rely on intensive management of soil, water, nutrient resources and pest populations.
Soil is vital to all crop production, whether sod, vegetables or fruit. Healthy and productive soil helps crops develop good root systems and reduces crop stress caused by drought or excess rainfall. Intensive production of horticultural crops creates some unique challenges in soil management.
Soil
erosion is a concern in many horticultural crops. Highly productive
land is valuable and the supply is limited. Water and wind erosion
can remove nutrients, other crop inputs, soil and organic matter.
The crops, themselves, may also be damaged or stressed by erosion,
increasing the possibility of disease. The following table shows a
number of practices available to reduce or stop erosion.
Erosion control structures, such as berms and terraces, are covered in the Field Crop Production book.
Soil erosion can be particularly destructive
to horticultural soils: removing crop inputs, soil and organic matter
and damaging or stressing the crop.
|
Erosion Type
|
Erosion Control Structures
|
Cover Crops
|
Tillage & Residue Management
|
Windbreaks & Wind Barriers
|
Strip Cropping
|
|---|---|---|---|---|---|
|
Water
|
X | X | X | | X |
|
Wind
|
| X | X | X | X |
X = Effective Control Possible

The impact of wind erosion is often underestimated. If soil is visibly moving, more than 11 tonnes/hectare of soil is being moved.
Most horticultural crops leave soil exposed. Even relatively small amounts of residue can reduce wind and water erosion.
Tillage and residue management involves leaving some crop residues to protect the soil. Residue acts in two ways:
To
protect soils, at least 20% residue cover should be left-but any amount
will help. See the Field Crop Production book for a more detailed
discussion of reduced tillage and equipment modifications.
A rye cover after processing tomatoes add organic matter, holds some excess nutrients and protects the soil over winter.
Cover crops are planted to protect the soil surface and to maintain soil structure. They also help tie up excess nutrients, add organic matter to soil and control pests. There is a variety of cover crops available. Some are suited for specific uses. You must know what you want from a cover crop when making the selection. Ask yourself the following questions:
| Top of Page |
| Cover Crop | Seeding Window |
|---|---|
| Winter Rye | LS, EF, LF |
| Winter Wheat | LS, EF |
| Barley | S, LS, EF |
| Oats | S, LS, EF |
| Ryegrass | LS, EF |
| Italian Ryegrass | ES, EF |
| Fescues | ES, EF |
| Corn | S, MS, LS |
| Sorghum-Sudan | ES, MS, LS |
| Cover Crop | Seeding Window |
|---|---|
| Red Clover | S |
| Ladino Clover | S, EF |
| Sweet Clover | S |
| Alfalfa | S, LS |
| Hairy Vetch | S, ES, MS, LS |
| Austrian Winter Peas | S, LS |
| Field Peas | S, ES, MS, LS |
| Soybeans | S, ES, MS, LS |
| Cover Crop | Seeding Window |
|---|---|
| Spring Canola | S, LS |
| Winter Canola | LS |
| Tame Mustard | S, LS |
| Oil Radish | S, LS |
| Cover Crop | Seeding Window |
|---|---|
| Buckwheat | S, ES, MS |
S = Spring; ES = Early Summer; MS = Mid Summer
LS = Late Summer; EF = Early Fall; LF = Late Fall
| Cover Crop | Fast Growing | Deep Tap Root | Fixes Nitrogen | Frost Tolerant | Killed Over Winter | Volunteer Seed Potential Weed Problem | Supports Nematodes* | |
|---|---|---|---|---|---|---|---|---|
| Lesion | Root-knot | |||||||
| Winter Rye | X | | | X | | | +** | ^ |
| Winter Wheat | | | | X | | | + | ^ |
| Barley | | | | X | X | | + | ^ |
| Oats | | | | X | X | | + | ^ |
| Ryegrass | | | | X | | | ^ | ^ |
| Italian Ryegrass | X | | | | X | | ^ | ^ |
| Fescues | | | | X | | | ^ | ^ |
| Corn | X | | | | X | | ++ | ^ |
| Sorghum-Sudan | X | | | | X | | O | ^ |
| Cover Crop | Fast Growing | Deep Tap Root | Fixes Nitrogen | Frost Tolerant | Killed Over Winter | Volunteer Seed Potential Weed Problem | Supports Nematodes* | |
|---|---|---|---|---|---|---|---|---|
| Lesion | Root-knot | |||||||
| Red Clover |
|
|
X
|
X
|
|
|
++
|
+++
|
| Ladino Clover |
X
|
|
X
|
X
|
|
|
++
|
+++
|
| Sweet Clover |
|
X
|
X
|
X
|
|
|
^
|
^
|
| Alfalfa |
|
X
|
X
|
X
|
|
|
^
|
+
|
| Hairy Vetch |
|
|
X
|
X
|
|
|
++
|
+
|
| Austrian Winter Peas |
|
|
X
|
X
|
?
|
|
+
|
+
|
| Field Peas |
|
|
X
|
X
|
X
|
|
+
|
+
|
| Soybeans |
X
|
|
X
|
|
X
|
|
+
|
+
|
| Cover Crop | Fast Growing | Deep Tap Root | Fixes Nitrogen | Frost Tolerant | Killed Over Winter | Volunteer Seed Potential Weed Problem | Supports Nematodes* | |
|---|---|---|---|---|---|---|---|---|
| Lesion | Root-knot | |||||||
| Spring Canola |
X
|
X
|
|
X
|
X
|
X
|
O
|
O
|
| Winter Canola |
X
|
X
|
|
X
|
?
|
X
|
O
|
O
|
| Tame Mustard |
X
|
X
|
|
X
|
X
|
X
|
O
|
O
|
| Oil Radish |
X
|
X
|
|
X
|
X
|
X
|
O
|
O
|
| Cover Crop | Fast Growing | Deep Tap Root | Fixes Nitrogen | Frost Tolerant | Killed Over Winter | Volunteer Seed Potential Weed Problem | Supports Nematodes* | |
|---|---|---|---|---|---|---|---|---|
| Lesion | Root-knot | |||||||
| Buckwheat |
X
|
|
|
|
X
|
X
|
+++
|
O
|
Note: Seeding success dependent upon weather, particularly
summer seedings.
*Varietal difference in cover crop species may affect nematode reaction.
**Rye-whole season rating would be higher (+++)
X = Exhibits this characteristic usually
? = Inconsistent in some locations
= Not applicable
^ = Poor or non-host
+ = Ability to host
O = Some cultivars are non-hosts
Windbreaks and wind barriers are covered in detail in the book
on Farm Forestry and Wildlife Habitat Management. Wind barriers
include a variety of possibilities, from short-term grain interseedings
in muck crops to grass strips and fence-like materials to protect
vegetables. Barriers reduce the speed of wind and lower its ability
to carry soil. The area protected by a tree windbreak is about 10
times its height. The amount of protection provided by other types
of barriers varies depending on height and the flexibility of the
material.

Wind barriers reduce the speed and soil carrying ability of the wind. Tree windbreaks protect an area about ten times their height. Grass wind barriers are more flexible and can be pushed down by high winds, reducing the protected distance to five to seven times the barrier height.
Strip cropping involves planting strips or sections of a field with crops having different growth habits. For example, growers may alternate strips of early vegetables with later-seeded vegetables. Although management may increase, the soil surface is better protected.
| Top of Page |
Maintaining
good soil structure is also a challenge for growers of intensively
managed crops. Soil structure refers to how well soil particles are
organized and held together as soil crumbs or clods. Structure influences
the general health of the crop in the following ways:
A good root system is essential to production, allowing the plant to exploit soil water and nutrients.
Tillage
and cultivation tend to break down soil clods and organic matter.
Organic matter is the glue that holds soil particles together. Production
of high-quality horticultural crops requires timely operations. Sometimes,
this means tilling, spraying or harvesting on soils that are too wet.
In addition, to be cost-effective, many of these operations have become
highly mechanized. Running heavy equipment in wet conditions may cause
soil compaction. Compaction means that the soil has become packed
and pore spaces are reduced which decreases the soil’s ability to
hold both air and water.
Scheduled harvest of perishable crops sometimes forces working on wet soils. Try to avoid compaction using other measures and plan to rotate away from the problem crops.
Tillage
and crop roots usually break up shallow or surface compaction. However,
deep compaction or plow pans can be more difficult to deal with. Deep-rooted
crops and frost action may help. Research shows that frost takes at
least three winters to reduce compaction, assuming that no further
compaction has taken place. Deep tillage or subsoiling is a prescription
treatment for the worst areas.
Given the soil conditions, this
deep tillage implement is where it should be - parked. Subsoiling
must be done properly, or problems can be made worse.
It is important to subsoil properly or compaction is just moved deeper:
Subsoiling is only a temporary solution and does not remove what caused compaction in the first place.
| Top of Page |
Soil
organic matter is a very small part of the soil with a large role
to play. Many soils used in horticultural production have soil organic
matter levels between 2 and 4%. About 40 to 45% of the soil organic
matter is very stable and resists decomposition. Another 40 to 45%
is moderately stable. This portion is protected or held within soil
clods and on clay particles and is very important to soil fertility,
accounting for 40 to 50% of nutrients released each year. The remaining
10 to 15% is composed of living and dead organisms and decomposes
easily.
Reducing tillage where possible will help to retain soil productivity by reducing soil compaction and erosion losses of soil and organic matter.
Growers can directly affect the organic content of their soils. Excessive tillage, soil erosion and poor crop rotation will speed loss of organic matter. On the other hand, there are a number of practices that maintain and improve organic matter:

Organic matter is only a small portion of the soil, but it is very important to soil fertility and good soil structure. Maintaining adequate soil organic matter levels is crucial to consistent production of horticultural crops.
| Introduction
| Understanding the
Basics | Vegetables
| Fruits | Greenhouse
Production | Tobacco
|
| Nursery Crops
| Sod Production |
References
| Table of Contents
|
| Top of Page |
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