ABOUT LETTUCE AND GREEN-LEAF CROPS
IRRIGATION OF LETTUCE AND GREENLEAF CROPS
The purpose of irrigation is to prevent water stress, especially during the formation of the part of the plant that will be harvested.
Water stress can occur in a crop when the soil moisture is excessive or when it’s deficient. When oxygen concentration levels in the soil atmosphere are lowered due to displacement by water for an extended period of time, the root system can be severely damaged.
Lettuce and green-leaf plants are especially susceptible to water stress due to their shallow root systems.
Water stress can lead to two main problems:
Moisture deficiencies occurring early in the crop cycle may delay the maturity season and reduce yields.
Shortages later in the season often lower quality, as well as yields. However, irrigation surplus, especially late in the season, can reduce both the quality and the post-harvest life of the crop.
Uneven or surplus irrigation, above the amount required to replace evapotration, causes nitrate leaching below the root system and the ability of the crop to recover from the nitrogen deficiency decreases.
Efficient water use, namely irrigation scheduling, high uniformity of water distribution and light precipitation rate, will help prevent stress conditions.
WATER REQUIREMENT CALCULATION:
Range of crop factor is 0.25-0.9.
The crop factor is related to canopy coverage:
Canopy coverage = Ca x Cb
Ca= coverage between plants (%)
Cb= coverage between rows (%)
Water requirement = daily ET (Evapotranspiration) x crop factor.
Potassium and phosphorus are recommended at the start of the season. Nitrogen is recommended during the growing season. Using Nitrogen in nitrate form helps to minimize tip burn.
High investment costs are associated with producing green-leaf crops. Selecting the most suitable irrigation system and managing it efficiently is crucial for success.
NaanDanJain offers a number of solutions: Irristand sprinklers or drip systems are ideal for open field, while inverted micro-sprinklers are best for greenhouse irrigation.
The IrriStand system for lettuce and green-leaves is a low-flow sprinkler that simulates light rain. Based on a flexible in-and-out solid-set PE system, the system successfully meets all crop requirements at all stages of development:
Main system advantages
High distribution uniformity and low application rate, at frequent irrigation cycles, provide maximum control and monitoring of the wetted and aerated soil profile, which is essential for the shallow root system of the lettuce.
Low application rate (3-5 mm/h): allows optimal absorption of water into the soil with no run-off, even on slopes.
Low droplet impact: preserves soil structure and prevents crust formation to allow perfect germination and development.
Short irrigation cycles: prevents stress caused by water surplus; provides optimal growing conditions with highly accessible moisture and nutrients in a controlled wetted and aerated soil profile; and ensure no nitrate leaches below the root zone and leakage into the groundwater.
Based on the IrriStand concept, ELITE is a solid-set system including 50 mm PE pipes with 10-12 meter segments. The system is flexible, portable and easy to operate.
SPRINKLERS FOR IRRISTAND AND ELITE SYSTEMS
NaanDanJain has developed a wide range of sprinklers for the irrigation of lettuce and green-leaf crops.
Characterized by their sturdy construction, corrosion resistance and extremely high water distribution uniformity, they respond to the specific field conditions.
SERIES OF 1/2” SPRINKLERS WITH LOW PRECIPITATION RATE
Characterized by excellent water distribution uniformity and reliability at low pressure conditions.
Compact ball-driven sealed mechanism for • spacing up to 12 m Available with flow regulator
Low flow single or double nozzle for spacing up to 12 m
Single larger nozzle concept with unique SD hammer for spacing up to 14 m
Single larger nozzle concept with unique SD hammer for spacing up to 16 M. Improved wind resistance
LPD for IrriStand (IrriStand Leakage Prevention Device)
NaanDanJain has developed a special drip concept to meet the needs of lettuce and green-leaf crops. The wetted uniform strip is based on low flow rate drippers, close dripper spacing and excellent uniformity. The drip irrigation concept combines accurate water and fertilizer applications.
The Wetted Strip
The concept of a continuous wetted strip creates optimal growing conditions for densely cultivated crops with shallow roots, such as lettuce. This prevents the deep percolation of water and nutrients under the shallow root system into the ground water, which can create pollution.
Product Selection and Design
Based on the particular agro-technical needs of lettuce crops, two main products are highly recommended:
Economical thin walled drip tape
Basic Design Recommendations
Drip lateral spacing: one lateral for two closed rows
Dripper spacing: 15-30 cm, depending on soil type
Dripper flow rate:
Tal Drip: 0.6, 1.0 l/h
Chapin BTF: 4.8 l/h per meter (0.96 l/h per outlet)
DOUBLE SYSTEM CONCEPT
Based on farmers’ needs and specific field conditions, NaanDanJain has developed the double system solution:
sprinklers (portable Irristand system) and drip, for maximum potential.
Stage 1: Soil preparation and bed cultivation, using over-head Irristand system
Stage 2: Pre-season application of chemicals, using Irristand
Stage 3: Germination or seedling establishment, using Irristand
Stage 4: Irrigation and fertigation throughout the season, using the drip system
Stage 5: Technical irrigation, such as cooling and dust washing, using Irristand
The Irristand system can be shifted from plot to plot, for germination purposes only.
SOLUTIONS FOR GREENHOUSE LETTUCE CROPS
Greenhouses, tunnels or net houses improve the growing conditions of lettuce and green-leaf crops.
NaanDanJain has a targeted solution for these conditions:
A range of inverted micro-sprinklers, installed under the greenhouse roof.
A wide range of flow rates to match the specific precipitation rate required, according to the optimal irrigation time. User-friendly software (the “Space”), especially adapted to greenhouse and tunnel conditions to achieve maximal uniformity (CU 88-95%) of design.
THE SINGLE LINE AND ANTI-MIST CONCEPT
NaanDanJain has developed a specific solution for tunnel conditions, taking into consideration the tunnel shape and the required needs, in order to achieve optimal effective irrigation. The single line creates a uniform strip with relatively big droplets and higher precipitation rate. It is suitable for tunnels up to 6.0 m in wide. Wider tunnels require 2-3 lines.
Recommended Inverted Micro-Sprinklers
The common guideline for all models is: height of installation is 120-200 cm above crop level, or as per the local conditions. All models are compatible with LPD (Leakage Prevention Device).
THE SINGLE LINE AND ANTI-MIST CONCEPT
NaanDanJain has developed a specific solution for tunnel conditions, taking into consideration the tunnel
shape and the required needs, in order to achieve optimal effective irrigation.
The single line creates a uniform strip with relatively big droplets and higher precipitation rate. It is suitable for tunnels up to 6.0 m in wide. Wider tunnels require 2-3 lines.
The benefits :The side by side layout, using the anti-mist device, achieves maximum uniformity at specific wetted strip.
High precipitation rates
Allows irrigation over a shorter time scale and causes reduced humidity, resulting in plants staying dry longer.
NaanDanJain’s unique combination of nozzle and anti-mist provides an ideal solution to this traditional greenhouse irrigation problem.
NaanDanJain is committed to finding the ideal solution for your lettuce and green-leaf crop tailored to your local climatic conditions, soil and water properties and budget.