Seeds play a crucial role in plant reproduction and form the basis of much of our food. Birds and insects scatter berries and other fruits, sand, gravel and other debris carry pine seeds on the wind, and many plants — including trees — produce buoyant spores that float to new locations.
A seed becomes a plant through germination, which is the process of sprouting or turning into a seedling. This can be triggered by several factors including the absorption of water, temperature and light exposure.
The first step in germination is the absorption of water, which is called imbibition. This causes the seed to rehydrate and expand its cells, and enzymes that have been inactive during dormancy become activated.
Some seeds must be dispersed to a suitable place for germination to begin. For example, stingless bees help to disperse the seeds of cadagai eucalypts by carrying them away from the parent plants. Other seeds rely on environmental cues to break down physiological dormancy. For example, the seeds of hakeas and banksias can keep for years in their woody fruits until a bushfire prompts them to germinate.
The thin layer of material that covers the earth’s surface known as soil is a complex mixture of biotic and abiotic elements. It contains mineral particles from the weathering of rocks, decayed organic matter, microorganisms, humus, water, and air. The soil’s natural fertility is essential for crop production.
To prepare the soil, farmers must first select the appropriate equipment for tillage. Then, they must water the field. This process loosens the soil and encourages microorganism growth, which enriches the soil with humus and other nutrients.
The next step is to prepare the seedbed. This involves removing any excess trash and debris from the field. It is also a good time to add compost and other soil amendments. The soil should be dry enough to work with, but not too wet.
Soil fertility provides a habitat for plant growth and supports the biotic community. It enables humans to grow and eat healthy food, supports economic development and fights poverty, reduces soil erosion and air pollution, regulates water resources availability and enhances carbon sequestration.
All soils differ widely in the concentration of nutrients necessary for crop production. The best-fertile soils contain optimal amounts of humus, clay particles with small surface areas and high nutrient retention capacities and coarse, sandy or loamy particles with large surfaces to promote rapid nutrient exchange.
All crops require a balanced supply of the main macronutrients nitrogen, phosphorus and potassium plus micronutrients (boron, chlorine, iron, manganese, magnesium, sulfur, zinc and molybdenum). This is achieved by using organic and inorganic fertilizers. The best results are obtained when a suitable fertilizer is chosen for the specific situation.
Seeds must absorb water to activate metabolic processes required for germination. The seed then requires oxygen to grow a root and shoot and survive.
Water is also needed to maintain turgor pressure, which is the force holding cell walls together during a plant’s growth. Uptake of water also helps break down stored starches, proteins, and lipids into smaller molecules that can be utilized by the seed.
It is important to water your Seedsheet garden carefully and often enough so that the soil stays evenly moist. The amount and frequency of watering is influenced by external environmental factors such as temperature, humidity, and sun exposure. Please check the soil in your seedling trays a few times a day to see how damp they are. Do not water to the point of displacing the top and bottom film of the Seedsheet pods.
The harvesting process can significantly affect seed quality. Proper harvesting ensures that only the best seeds are saved for future planting, which will result in a healthier plant that can produce more beautiful flowers, fruits and vegetables.
Seeds that grow inside pods, such as those of runner beans, okra and peas, must be harvested before they burst open. To check whether pods or seeds are ready for harvesting, gently tap a flower head, fruit or seed pod and listen for a rattle or a crackle.
Once the seeds have been collected, they need to be cleaned of chaff before storing. This can be done in a number of ways, including threshing or smashing; shaking; sieving; and winnowing (dropping the seeds into a bucket and blowing away the lighter chaff). The seeds need to be dry before storing.