Construction Of Automatic Moisture Controller

ABSTRACT

Moisture is essential for seed germination. Soil moisture and temperature are the two most important factors controlling germination, the start of root growth and emergence. Soil moisture is critical as it affects how quickly water penetrates the seed. Adequate soil moisture: promotes root growth, promotes a large abundant leaf area, helps plants retain their leaves longer, lengthens the flowering period and increases the number of branches per plant, number of flower forming pods, seeds per pod, seed weight, and seed yield. However, too much or too little moisture at any particular growth stage reduces yield potential.

In order not to have too much or too little, automatic moisture is used, which is an instrument that measures the volumetric water content in soil. Since the direct gravimetric measurement of free soil moisture requires removing, drying, and weighting of a sample, soil moisture controller measure the volumetric water content indirectly by using electrical resistance property.

CHAPTER ONE

1.0                                                        INTRODUCTION

Water is essential for plant growth. Too much or too little water at any particular growth stage reduces yield potential.

Water is the major component of plant. It plays an important role in nutrient absorption and transportation, formation of new products, plant growth and plant response to abiotic stresses. Carbohydrates, the products of photosynthesis, are moved in water solution to storage organs. A major portion of the water absorbed by the canola plant evaporates through the stomata (tiny pores in the leaves). This evaporation process called transpiration is essential for absorbing oxygen for photosynthesis. In addition, water absorbs heat, cools the plant and prevents plant injury from high temperatures. Water is also lost directly from the soil surface by evaporation. The combined loss of moisture from the soil and the plant is called evapotranspiration. Heat and wind increases evapotranspiration by rapidly removing and changing the air surrounding plants.

A firm moist seedbed provides uniform seed germination and rapid seedling growth. Adequate soil moisture at the seedling and elongation stage promotes the development of a strong, healthy plant less subject to lodging with a maximum amount of leaf growth by the end of June. Leaves provide the predominant source of food for seed development. Therefore, water management practices that increase leaf development and prolonged leaf life will also promote seed development.

This work is on Soil moisture controller which is a device that measures the volumetric water content in soil. Since the direct gravimetric measurement of free soil moisture requires removing, drying, and weighting of a sample, soil moisture controller measure the volumetric water content indirectly by using some other property of the soil, such as electrical resistance, dielectric constant, or interaction with neutrons, as a proxy for the moisture content, but in this work electrical resistance method is used,   The relation between the measured property and soil moisture must be calibrated and may vary depending on environmental factors such as soil type, temperature, or electric conductivity.

1.2                                                   AIM OF THE PROJECT

The aim of this project is to provide an efficient solution for detecting and controlling soil moisture using soil moisture sensor. The microcontroller forms the heart of the device and there are also soil moisture sensors, which are meant for detecting the moisture in the soil.

1.3                                         SIGNIFICANCE OF THE PROJECT

The Soil Moisture Sensor durably and electronically measures the temperature differences in the soil, and derives the moisture of the soil from these – precise and reliable. If the battery is weak, this is indicated. It indicates when the battery needs to be charged.

1.4                                              PURPOSE OF THE PROJECT

The purpose of this project is to monitor and control soil moisture using soil moisture sensor. This can be achieved by the use of soil moisture sensor, which senses the water content in the soil.

1.5                                          APPLICATION OF THE PROJECT

Agriculture

Measuring soil moisture is important for agricultural applications to help farmers manage their irrigation systems more efficiently. Knowing the exact soil moisture conditions on their fields, not only are farmers able to generally use less water to grow a crop, they are also able to increase yields and the quality of the crop by improved management of soil moisture during critical plant growth stages.

Landscape irrigation

In urban and suburban areas, landscapes and residential lawns are using soil moisture sensors to interface with an irrigation controller. Connecting a soil moisture sensor to a simple irrigation clock will convert it into a “smart” irrigation controller that prevents irrigation cycles when the soil is already wet, e.g. following a recent rainfall event.

Golf courses are using soil moisture sensors to increase the efficiency of their irrigation systems to prevent over-watering and leaching of fertilizers and other chemicals into the ground.

Research

Soil moisture sensors are used in numerous research applications, e.g. in agricultural science and horticulture including irrigation planning, climate research, or environmental science including solute transport studies and as auxiliary sensors for soil respiration measurements.

Simple sensors for gardeners

Relatively cheap and simple devices that do not require a power source are available for checking whether plants have sufficient moisture to thrive. After inserting a probe into the soil for approximately 60 seconds a meter indicates if the soil is too dry, moist or wet for plants

1.6                                           LIMITATION OF THE PROJECT

Faulty sensors can give incorrect results. That is, when the sensor is dirty it can cause the device to display or indicates incorrect results.