Winter & Spring Pasture Growth Using Liquid Fertiliser, Growth Enhancers, and Biological Systems
Winter & Spring Pasture Growth Using Liquid Nitrogen and Biological Systems
Winter and early spring are traditionally the most difficult periods for maintaining pasture growth across New Zealand farming systems.
Cold soils, wet conditions, and reduced biological activity limit nutrient availability, slowing pasture growth at the very time feed demand begins to rise.
Modern liquid nutrient systems, combined with biological inputs and plant growth enhancers, are increasingly being used to maintain pasture growth and improve nitrogen efficiency during this period.
Why Pasture Growth Slows in Winter
Several key factors restrict pasture growth through winter:
Cold Soil Temperatures
Granular nitrogen fertilisers rely on soil-based processes to become available to plants. In cold soils, these processes slow significantly, delaying plant uptake.
Liquid foliar nitrogen systems bypass some of these limitations by allowing nutrients to be absorbed directly through the leaf, helping maintain growth even under challenging seasonal conditions.
Reduced Soil Biology
Winter conditions often reduce microbial activity in soil.
This limits:
• Nutrient cycling
• Organic matter breakdown
• Root activity
• Nitrogen availability
Biological inputs such as seaweed, humates, and fish-based fertilisers are commonly used to support microbial activity and improve nutrient availability
The Role of Liquid Nitrogen in Winter Growth
Liquid nitrogen fertilisers provide a flexible method of delivering nutrients during periods when soil-based systems are less effective.
These solutions are fully dissolved, allowing:
• Even distribution across plant surfaces
• Consistent uptake
• Reduced reliance on soil temperature
• Accurate application rates
Liquid nitrogen solutions containing sulphur, seaweed, and humates support protein formation and nitrogen utilisation within the plant, improving growth efficiency.
Growth Enhancers: Gibberellic Acid and Triacontanol
Plant growth regulators (PGRs) play an important role in stimulating plant development during cooler conditions.
Gibberellic Acid
Gibberellic acid is a naturally occurring plant hormone responsible for:
• Cell elongation
• Leaf growth
• Root development
• Early growth stimulation
When applied correctly, it encourages plants to initiate growth earlier in cooler conditions.
Triacontanol
Triacontanol is a naturally occurring plant compound known to enhance:
• Photosynthesis
• Dry matter production
• Nutrient efficiency
• Plant metabolism
When combined with nitrogen fertiliser, it supports improved growth response and biomass production.
Biological Inputs: Seaweed, Humates and Fish
Biological inputs support both plant growth and soil function.
Seaweed Extract
Seaweed provides:
• Natural plant hormones
• Trace minerals
• Stress tolerance compounds
• Root development stimulation
Humates
Humates improve:
• Soil structure
• Nutrient retention
• Microbial activity
• Root-zone health
Liquid Fish Fertiliser
Liquid fish fertilisers supply:
• Natural nitrogen
• Amino acids
• Organic nutrients
• Microbial food sources
These biological inputs help support soil microbial populations, improving nutrient cycling and long-term soil productivity.
One of the Biggest Advantages — Combining Applications
One of the major advantages of liquid nutrient systems is the ability to combine multiple products into a single spray pass.
Liquid nitrogen and biological products can often be applied alongside:
• Herbicides
• Porina control products
• Grass grub treatments
• Weed control programs
This allows:
• Reduced machinery time
• Lower fuel use
• Reduced labour costs
• Improved efficiency
Liquid nitrogen systems are commonly applied during weed or insect spray operations, helping reduce overall application costs.
Case Study — New Zealand Dairy Farm
A dairy farmer reported switching to liquid nitrogen and growth enhancers primarily to improve winter feed supply.
They reported:
“Our main reason for changing to liquid is the 100% uptake and we are only using half the units of N.”
Additional benefits included:
• Reliable winter growth
• Fast pasture response
• Reduced nitrogen use
• Flexibility in application timing
Another farmer noted the advantage of being able to apply liquid fertiliser quickly across large areas, reducing labour time and improving efficiency
Reducing Nitrogen Inputs Without Reducing Growth
Nitrogen efficiency is becoming increasingly important due to:
• Environmental regulations
• Rising fertiliser costs
• Farm sustainability goals
Strategic use of nitrogen, sulphur, biological inputs, and growth enhancers can help achieve strong pasture response while reducing total nitrogen applied.
In some systems, nitrogen use reductions of up to 50% have been achieved while maintaining pasture productivity.
Practical Winter and Spring Application Strategy
Typical seasonal approach:
Early Winter
Maintain base growth
Support root activity
Late Winter
Stimulate early growth
Prepare pasture for spring demand
Early Spring
Accelerate rotation speed
Maximize feed availability
Increase silage yields and between cuts
Who Should Consider Liquid Growth Systems?
These systems are commonly suited to:
• Dairy farms
• Sheep and beef operations
• Winter milk systems
• High stocking rate farms
• Farms aiming to reduce nitrogen inputs
Frequently Asked Questions (FAQ)
Can liquid nitrogen replace granular nitrogen?
In many cases, liquid nitrogen can replace or supplement granular nitrogen applications depending on system requirements.
Can these products be mixed with herbicides?
Many liquid nutrient products are compatible with herbicides and insecticides, allowing multiple operations to be completed in one spray pass. Always confirm compatibility before mixing.
Does liquid nitrogen work in cold weather?
Liquid foliar nitrogen is less dependent on soil temperature compared to granular nitrogen, making it suitable for winter use.
Can biological inputs reduce fertiliser requirements?
Biological inputs can improve nutrient efficiency and soil function, helping reduce total fertiliser requirements over time.
The Importance of Sulphur and Phosphate in Winter and Spring Growth
While nitrogen often receives the most attention, sulphur and phosphate are critical supporting nutrients that significantly influence pasture response.
Balanced nutrition improves nitrogen efficiency, plant metabolism, and root development — all essential during cooler months.
The Role of Sulphur in Pasture Growth
Sulphur plays a key role in nitrogen utilisation and protein formation within pasture plants.
Without adequate sulphur, plants cannot fully utilise nitrogen, resulting in reduced pasture response even when nitrogen is applied.
Sulphur supports:
• Amino acid and protein formation
• Nitrogen conversion within the plant
• Chlorophyll production
• Improved pasture colour and vigour
• Increased dry matter production
Sulphur deficiency is commonly observed during winter and early spring due to:
• Leaching losses
• Reduced mineralisation
• Limited soil biological activity
Including sulphur alongside nitrogen applications helps maximise nitrogen efficiency and improve pasture growth consistency.
Liquid nitrogen products containing sulphur provide an effective method of delivering both nutrients simultaneously, supporting plant uptake during cooler periods.
The Role of Phosphate in Early Season Growth
Phosphate is particularly important during periods of root development and early seasonal growth.
Phosphorus is responsible for energy transfer within the plant, making it essential for:
• Root development
• Early shoot growth
• Plant establishment
• Energy movement within plant cells
• Improved recovery following grazing
Cold soil temperatures can limit phosphate availability, reducing early-season pasture response.
Liquid phosphate options provide a flexible method of supplementing phosphate when soil supply is limited or when rapid plant response is required.
Combining phosphate with nitrogen and biological inputs supports stronger root systems and improves long-term pasture resilience.
Balanced Nutrition Improves Nitrogen Efficiency
Nitrogen response is rarely determined by nitrogen alone.
Strong pasture growth requires:
✔ Nitrogen — for leaf growth
✔ Sulphur — for protein formation
✔ Phosphate — for energy and root growth
✔ Biological inputs — for soil and plant function
Balanced nutrient programmes consistently outperform nitrogen-only systems, particularly during winter and early spring.
Winter and early spring pasture growth remains one of the most important drivers of farm productivity, and is achievable when soil temperatures are over 5deg C.
Liquid nitrogen, sulphur, phosphate options, combined with biological inputs and plant growth enhancers, provide a practical and increasingly common method of improving pasture performance, reducing nitrogen use, and improving overall farm efficiency.