Effect of Biochar and Plant Based-Irrigation Scheduling on Growth and Plant Water Use.

Inefficient use of irrigation water can exacerbate water shortages, not only in times of drought, but also during non-drought periods. Developing management practices that make more efficient use of irrigation water is important for improving the sustainability of nursery crop production. Biochar, a byproduct of pyrolysis, is becoming increasingly available for use in agriculture. Incorporating biochar into nursery substrates can potentially increase water holding capacity and reduce water leaching. Additionally, estimating plant water use by measurements tied to the physiological status of the plant conserves water. The objective of this research is to determine the effect of biochar and irrigation scheduling (plant physiology-based and substrate physical properties-based) on water requirement and leachate mitigation for hydrangea (H. paniculata ‘Silver Dollar’). Pots were filled with pine bark and amended with either 10% or 25% by volume of biochar. Plants were irrigated with a moisture sensor-based irrigation system that provided the prescribed volume of water to maintain photosynthesis at 90% of the maximum predicted rate, or based on replacing the volume of water based on substrate physical properties. This suggests that integrating precise irrigation systems with proper irrigation scheduling can improve irrigation efficiency. In addition scheduling irrigation based on plant physiology or substrate physical properties in combination with low cost substrate amendment like biochar can reduce water requirement for high-value crops.