Project Overview
Commodities
- Nuts: chestnuts
Practices
- Crop Production: agroforestry, irrigation, water management
Summary:
Steady slow irrigation is generally the most optimal for plant growth, plant health, soil health, erosion control, and other agricultural aspects. Unfortunately the weather rarely rains in a steady slow stream; instead, plants are frequently stressed or killed by too much or too little water. Too much water can be somewhat controlled by cover crops and buffer strips, but these techniques are not widespread and can take time and money to develop. Too little water can be somewhat remedied by irrigation, but current irrigation methods can be expensive, complicated, and require large amounts of water.
Our specific application required providing regular moderate amounts of water to newly planted young chestnut trees. Current irrigation techniques are generally designed for high density gardens or annual crop fields, but commercial tree planting is done at large scale and low density (tens of trees per acre). These tree plantings are better modeled as discrete points that require water, rather than an entire field that requires uniform irrigation. Thus most trees are watered by hand using water from hoses and buckets with small holes to slowly drip water into the ground, or with custom irrigation setups grafted onto existing irrigation systems.
Our solution was clay pots with rain and dew catching sheets. Pots have been used for thousands of years as irrigation containers whose clay walls slowly transfer water from the pot to the surrounding soil, autoregulate by increasing irrigation in dry soil and decreasing irrigation in wet soil, provide water more directly to roots, and can be easily filled by hand. Rain and dew catching sheets were cut in 3 foot squares secured and supported by four poles, with one pole at each vertex of the square, to form an inverted pyramid which rain and dew trickled down the sides of to be collected in the pot.
Our research did not provide strong conclusions but did suggest beneficial practices and potential further areas of study. The containers and water catching sheets did measurably reduce soil moisture loss over time, but frequently had minor problems and irregular data. The containers and water catching sheets did not measurably impede or promote normal growth of the trees as compared to averaged growth of all other trees in the field.
There were no local farmer adoption actions. In different environmental settings, with infrequent heavy rains, high daily temperature variation, mild winds, sandy soil, and easy access to materials, these systems may be beneficial.
Project objectives:
The trials of this research project will use different configurations of pots and water collectors to maximize data gained, minimize costs, and quantify the influences of the many variables. Cylindrical pots will be buried an inch deep near a tree. Water collectors will be 3 foot squares that are secured and supported by four 2 foot high poles, with one pole at each vertex of the square, and a weight in the middle, to form an inverted pyramid which rain and dew will trickle down the sides of to be collected in the pot. A hole will be made in the sheeting to fit the tree into.
A majority of the pots and water collectors will provide an experimental baseline. The other trials will provide comparisons with modified configurations with an additional dew condenser, no water collector, and a small barrier designed to direct water flow more primarily towards the tree.
2 plastic pots impermeable to water and with water collectors will be used as controls for rain and dew to measure these as the water will be partially absorbed and distributed in the trials.
For controls we will measure the soil moisture of nearby areas of mulched trees without pots.
Rainfall will be measured locally using a rain gauge.
Our objective is to demonstrate the viability of pots with water collectors by measuring irrigation rate, dew collection rate, and soil moisture dispersion rate in a wide variety of trials, control configurations, and weather. The data will be collected during the growing season of second half of April to October, and analyzed and disseminated during the dormant season of November to first half of April.