Irrigation Management

Table of Contents
for the Irrigation Management BMP Booklet

INTRODUCTION

Potentially high-value crops such as fruits, vegetables, tobacco, sod and nursery stock must be of top quality to win acceptance in the marketplace. Attaining quality requires timely management decisions – especially of crop production inputs.

Water, in the form of precipitation or irrigation, is one of the most critical crop inputs. Natural rainfall can be unpredictable. Water must be supplied in sufficient quantity, of desired quality, when the crop needs it. By controlling your crop's water supply, you are controlling an essential production variable.

Beyond good soil management techniques, irrigation is the best management technique available to meet your crop's water requirements when natural rainfall is inadequate. This booklet will help you plan and implement best management practices to fulfill water needs profitably, safely and in an environmentally responsible way.

But irrigation does not suit every operation. Its benefits must outweigh its costs. Consider the following criteria before purchasing, modifying or simply assessing your irrigation system requirements.

Table potatoes need irrigation to attain high yields and quality.	A successful celery crop depends on irrigation.

With these considerations in mind, let's look at the reasons for choosing irrigation.

Each system demands differing degrees of labour input.	Where possible, irrigation ponds should be fenced and signed.

BENEFITS OF IRRIGATION

ESTABLISHMENT

• recently transplanted or seeded crops require water for root establishment /germination, especially tree fruits and nuts, berry crops, grapes, nursery stock and field vegetables.

GROWTH AND VIGOUR

• plants require water for all phases of growth, including cell division, cell elongation, photosynthesis and transpiration during the growing season – it is the process of transpiration that provides a cooling effect to the crop as it grows.

FLOWER-SETTING AND FRUIT DEVELOPMENT

• adequate water supply enhances fruit and flower bud formation (feathering in young trees), flowering, fruit set and fruit sizing.

QUALITY

• the flavour, appearance and post-harvest attributes of certain fruits and vegetables can be improved with water-efficient irrigation in situations where rainfall or available soil water is limited. In some situations, some fruit and vegetable crops may not respond positively to irrigation water in terms of flavour or sugar development. (This may be cultivar- and soil type-specific).

All crops require an adequate moisture supply for growth and development. Vegetative growth and early development are accelerated by irrigating and protecting this hazelnut or filbert planting.	Most high-value crops require properly timed and adequate moisture supplies. Irrigating fresh-market tomatoes enhances size, volume and texture of produce in a dry year.	Reliable and healthy transplant stock is what the landscape industry requires. Irrigation can help.

Irrigation helps a young peach orchard become established. Young trees need ample water for root development, shoot growth and fruit bud initiation. Overall, marketable yield is increased.

SPECIAL APPLICATIONS

• evaporative cooling to ensure quality fruit and continued crop development under conditions of excessive heat, e.g., strawberry, nursery stock;
• frost protection of high-value crops, e.g., tobacco, fruit, asparagus and berries;
• wind erosion protection of soil and crops in extreme conditions, e.g., tobacco;
• seedbed activation of direct-seeded vegetable crops, e.g., rutabaga, carrot;
• chemigation and fertigation: crop protection materials and necessary nutrient treatments can be applied at a lower cost to the producer. Fertilizer treatments are applied with surgical accuracy, e.g., tree fruits, nursery stock, berry crops, vegetables.

Irrigation can help you avoid losses of high-value crops. For example, frost damage can be prevented on strawberries with sprinkler irrigation during the bloom period.	Fertigation involves supplying water and nutrients at the same time. Compared to untreated checks, yield increases of up to 20% have been measured with the fertigation of high-value crops such as green peppers.

PROTECTING WATER RESOURCES

Irrigation depends on reliable supplies of fresh, clean water from surface and/or ground water sources. You must be aware of potential impacts that your irrigation system has on the quantity and quality of ground and surface water.

A large river like this one can be a suitable source of water. However, wetlands and smaller watercourses are not as well suited to irrigation.	Taking large amounts of water from ground water can lower levels in wetlands, small streams and nearby wells.

DESIGN, MATERIALS AND MANAGEMENT

The main components of an irrigation system are design, materials and ongoing management.

Design must take into account your crop's needs and response along with the environmental concerns listed in the previous chart. Materials include power source, pumps, conduit pipes, emission points and monitoring devices. Ongoing management includes monitoring, record-keeping, scheduling and application.

Irrigation technology is improving, responding to growers' demands for more efficient systems. Newer systems meet crop needs with more efficient distribution of water. Gentler application methods help maintain soil structure, avoiding compaction problems.

Trickle irrigation systems can deliver water to where the crop needs it, efficiently and economically, as shown here with high-density apples on M9 rootstock.	Irrigation can help growers service niche markets with more predictable volumes of high-quality produce.

INDUSTRY STANDARDS FOR MEASUREMENT

Last revised: Sunday, May 03, 2009 03:40:20 PM