Tree Fertilizing Health Care Program Factsheet & Sustainable Soil Fertility In Urban Forests

Trees in urban areas face various obstacles and stresses. Trees planted between sidewalks and roads or between buildings and roads are often hindered in their ability to obtain the nutrients needed for growth and development. Soil compaction caused by car traffic or heavy foot traffic over a tree’s roots can cause root damage and impair the tree’s capacity to receive nutrients. In some cases, mechanical wounding agents ‒ lawn mowers, vehicles etc. ‒ can visibly scar a tree, interrupting nutrient movement between the roots and the crown.

An AQF level 5 Arborist can consult and advise cost-saving tree fertilising Health Care Program techniques and sustainable management strategies to ensure the health, quality and safety of trees on your development property.

Trees In Urban Forests React Differently To Trees In Their Natural Settings

Nutrient deficiency symptoms are uncommon in trees and shrubs living in their natural settings. This can be attributed to natural nutrient recycling and the fact that plants in the wild often grow only in environments that they are most adapted to or where they have a competitive advantage.

Trees in urban forests have their natural nutrient cycles disrupted by roadworks, maintenance practices or planting schemes. They may also be forced to adapt to soil compositions that do not occur in their natural habitats. 

For these reasons, it is essential to establish cultural practices that sustain or replenish soil organic matter and nutrients. An important aspect of sustainable soil management is periodic fertiliser application, especially in commercial and residential landscape settings.

An effective IPM or Plant Health Care programme is developed around maintaining soil fertility and paying attention to plant nutritional requirements.

The Importance Of Fertiliser

Fertiliser supplies essential nutrients for plants to develop normally and remain healthy. Organic matter and soil are important nutrient suppliers, but in circumstances where the soil composition is imbalanced, fertilisation is beneficial. 

Fertilisers can:

  • Stimulate plant growth
  • Improve the colour, appearance and health of vegetation in urban forest settings

Soil Fact Sheet

Soil PH Levels: A soil fertility programme for trees and woody plants should begin with a soil pH analysis to test acidity levels. Soil pH is quantified on a scale ranging from 0 to 14. Acidic soils have a pH level of less than 7, whereas alkaline soils measure above 7.

A soil’s pH impacts the availability of nutrient elements as well as microbial activity; therefore, adjusting pH levels is vital for the health of both plants and ecosystems. 

Prior to any planting in nursery soils or on landscaping sites, the pH of the soil should be analysed. Generally, limestone is used to raise the pH, while sulphur is applied to lower it. However, it is advisable to introduce these compounds into the soil before planting since surface treatments are better applied when a  gradual effect on pH levels is required.

Soil Composition: Basic plant nutrition entails the absorption of sixteen mineral elements necessary for plant growth and development. Aside from carbon, hydrogen and oxygen, which may be obtained from air and water, the three essential compounds required in the greatest abundance for plant growth are nitrogen (N), phosphorus (P) and potassium (K).

  • Nitrogen affects the pace of cell proliferation (growth) and hence contributes to the formation of healthy twigs, wood and leaves. Nitrogen also promotes a tree’s chlorophyll synthesis, a deficiency of which results in chlorotic foliage. 
  • Phosphorus promotes root development and the availability of stored carbohydrates for growth during the spring seasons. 
  • Potassium, or potash, aids in the formation and flow of sugars and starches, as well as strengthening, toughening and maturing a tree’s different parts.

Soil Nutrient Ratios: Research in the nutritional requirements of trees and shrubs plants has shown that nitrogen is the ingredient that produces the most significant growth response. 

  • Trees and shrubs that are already established require fertilisers with high levels of nitrogen ‒ N-P-K ratios of 4-1-1, 3-1-1, or 3-1-2 are recommended.
  • Fertilisers with  8-2-2, 15-5-5, 24-8-16 ratios and similar compositions are also recommended. The analysis refers to the fertiliser’s percentages of nitrogen phosphorus (as P2O5) and potassium (as K2O) contained.

Phosphorus, potassium and other essential compounds often take longer to deplete in soils than nitrogen. As long as these nutrients are applied at the prescribed rates, fertiliser programs for both existing and introduced trees and shrubs in urban forests often consist entirely of nitrogen treatments. Complete fertilisers should be applied only if soil or leaf tissue tests reveal a severe deficiency.

Sustainable Soil Fertility In Urban Development

When it comes to urban development, the long-term maintenance and management of ecosystems begin at a development level. The responsibility rests with private, commercial and governmental entities to ensure the sustainability of soil fertility on their properties and jurisdictions.

This can be achieved by consulting with an AQF level 5 Arborist consultancy to ensure all the correct steps are taken. This includes: 

  • Design: Layouts are centred on plant requirements and site potential.
  • Contract: This must be drawn up so that all areas of development will meet the requirements of existing or planned vegetation.
  • Site preparation: Strategic site planning ensures suitable soil conditions and can provide cost-effective methods for soil fertility sustainability and nutrient retention.
  • Tree supply: In the case of planned landscaping, the plant material supplied must be of the greatest possible morphological, physiological and phytosanitary quality.  Trees must also be assessed to be capable of adapting to and reproducing in new environments.
  • Planting Intervention: Ensuring that all necessary interventions are taken before, during and after planting.
  • Establishment: Measures put in place to anticipate common urban challenges such as water shortages, weed competition and man-made damage.
  • Maintenance: Continued maintenance and integrated plant management programmes must be implemented based on plant types and lifecycle requirements. The belief that once trees are planted, they can exist on their own must be abandoned.
  • Monitoring: Native tree species and introduced trees in an urban setting must undergo regular inspection to identify stress and illness before they become a safety concern.

Treescience uses scientific principles for soil and plant health care and maintenance. We pride ourselves on innovation and can apply numerous cost-saving tree fertilising techniques and integrated plant management strategies designed to complement the surrounding ecosystems and build a healthier food soil profile.

Applying industry-leading methods such as Air Knife, Grow-gun, Microscopic Analysis and Wood/Soil DNA Sequencing eliminates speculation, providing a comprehensive understanding of a tree’s structure, underground root positioning and soil microbiology. We also work directly with Australia’s premier soil biology organisations devoted to sustaining urban forests.

To employ the consultation of an AQF Level 5 Arborist as part of your commercial, residential and commercial development application, get in touch with Treescience today. Together we can achieve sustainable soil fertility without hazardous and expensive chemicals.