What is Soil Fertility?
Soil fertility is the ability of soil to sustain plant growth by providing essential plant nutrients and favorable chemical, physical, and biological characteristics as a habitat for plant growth. It is the main factor in determining plant growth quality and quantity producing healthy food with the necessary nutrients.
Why Does Soil Fertility Need to be Conserved?
In a natural environment, soil is extremely fertile. In these circumstances soils naturally contain all nutrients necessary for plant growth. During the growth period plants continually will take up nutrients from the soil. After plants die nutrients are then released back into the soil. Which then conserves soil’s natural fertility, restarting the circular process of plant growth.
The Danger of Fertility Loss
Much of the natural soil fertility cycle has been interrupted and ended by many current farm practices by many current farm practices. One of said practices as tillage systems. Different from the natural cycle, tillage activity consumes nutrients and rids them from the soil as crops are harvested rather than returned to the soil. The consequence of this being that soil gradually becomes poorer through this process and losing their nutrient holding abilities, thus the soil eventually becomes infertile and unusable. Soil structure is completely broken, microbial activity comes to an end, and erosion is increased all as a result. This is one of the many reasons why it is necessary to conserve soil fertility through our agricultural activities. Paying attention to soil conservation is the first step of sustainable agriculture and fixing the soil fertility cycle.
How Does Soil Fertility Affect Plants?
Botanists have found that plants require sixteen essential elements for growth: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, zinc, boron, molybdenum, and chlorine. Soil provides all of these nutrients naturally with the exception of carbon, hydrogen, and oxygen. When one essential element provided by soil is insufficient, it leads to poor quality produce and weaker harvests. Yields and profits in turn suffer as the lower quality and amount comes to affect profit margins. Insufficient soil becomes weaker and weaker, eventually leading to arable land loss, or the loss of land capable of growing crops.
What Can We Do to Improve Soil Fertility?
A soil test is required to start the path to replenishing your soil fertility. It is important to understand the concentration and distribution of nutrients in your soil before fertilizing. In doing so, we can avoid excessive fertilization and environmental pollution. Another purpose of soil testing is to know that the ratio of nutrient elements. There are antagonist actions and synergist actions between different elements. For example, K, Ca, and Mg performs antagonist actions to each other, meaning they compete for the absorption from plants. When the potassium concentration exceeds the threshold, it reduces the amount of calcium and magnesium absorbed by the plants and vice versa. This is one of the many reasons why taking a soil test is important. It also can help the farmer apply fertilizers precisely and eventually reduces the cost of fertilization.
Approaches
There are three basic ways to replenish soil fertility: chemical fertilizer, organic fertilizer, and microbial fertilizer.
Chemical Fertilizer
Nutrients taken up by plants are in an inorganic form. Plants absorb these nutrient elements as they absorb water in which nutritional elements are dissolved. Most chemical fertilizers are water-soluble and this is the reason why chemical fertilizers can provide nutrients rapidly and easily. However, in comparison to organic fertilizers, chemical fertilizers are a limited resource. Many added nutrients can get locked in soil and actually add to soil degradation as chemicals crowd out the natural soil process. For sustainable agriculture, the use of chemical fertilizers should be decreased in favor of organic fertilizers.
Advantage: Rapid, Lower cost.
Disadvantage: Soil degradation, High energy-consumption.
Organic Fertilizer
With a long history in agriculture, organic fertilizer has always been a farmer favorite to increase crop yields. There are many kinds of organic fertilizers such as compost, vermicompost, kitchen-waste compost, green manure, animal manure, and more. The main purpose of organic fertilizers is not to provide plant nutrients directly, but to improve soil quality by increasing soil organic matter. In doing this it can increase soil fertility retention capacity, reduce soil degradation, and reduce erosion. Organic fertilizer is also a reusable resource which is an important component for sustainable agriculture.
Advantage: Improve soil properties, Sustainable agriculture.
Disadvantage: Slow-release, Must be used continuously
Microbial Fertilizer
Microbial fertilizer is a new revelation in fertilizers. Microbial fertilizers a supportive role in plant production. It not only can accelerate the decomposition of organic fertilizer in the soil and release nutrients but also increases the availability of insoluble nutrients, reviving soil that has been over farmed and derogated. Additionally, microbial fertilizers promote diversity in soil microbiomes and reduces the number of pathogens in soil.
Advantage: Eco-friendly, Multifunctional
Disadvantage: Initial pricing
Where We Go From Here
There is a saying “Soil is not left by parents, but borrowed from children.” Harmful chemicals and unsupportive agriculture practices are quickly riding our future generations of usable land. Farms passed down from generation to generation are at risk of losing their fertility and livelihood. It is important that we conserve soil fertility and property carefully as it is the only to achieve sustainable agriculture.
