Have you ever thought much about what plants need to grow? Being that plants are alive, they need some of the same things that you do to survive (think Maslow's hierarchy of needs, but plant version). Most notably plants need sun, water, air, stable temperatures and food; among other things. That being said, this is not an all inclusive list and there are other variables to whether your seeds will germinate and grow into a well producing plant.
If you ever went to an elementary school science fair, you probably learned that plants need sunlight to grow. While seeds begin their life underground in the dark, once they break through the soil they all need some sun to survive. Some need more than others. Plants such as sunflowers, tomatoes, peppers, peas, and many more need “full sun” or 6-8 hours of sun per day to reach their full potential. Others like your leafy greens prefer shaded areas because they would burn in full sun.
Water aids plants in photosynthesis and helps regulate their temperature. Watering the soil when it is dry benefits root development and helps the plant draw up nutrients from the soil.
Plants need air to “breathe”. They do this through photosynthesis, where they take in carbon dioxide and release oxygen through their leaves. In cellular respiration they take in oxygen and release carbon dioxide.
Like humans and animals, plants need food. This is the category that usually gets forgotten or overlooked, due to the complexity of a plants nutrition requirements. Plants can typically grow in just any old soil, but in order for you to have a booming garden, field, or food plot; helping your plants out would be advised. Knowing what category of soil (sandy, loam, or clay) you're planting in can help as different plants perform better in certain soil types.
If you want to help your plants reach their potential; knowing where your soil is deficient and then preparing amendments and adding fertilizers should do the trick! Macronutrients such as nitrogen, phosphorus, and potassium, plus important micronutrients, and soil pH, all play a key role in the success of crops. Soil characteristics and nutrient levels vary from place to place; so performing a simple soil test is the best and most accurate way to know what kind, and how much, fertilizer to add!
Good luck and happy gardening!