Manure has some potential disadvantages when used as fertilizer. It can contain weed and pest seeds, rodents and other pests, and pathogens such as E. coli. It can also cause pollution if not managed properly, as the manure may flow into the surface or groundwater.
Disadvantages of Manure
The manures are reported to provide fewer nutrients to plants, and they are unable to provide high-yielding crops. Manures are slowly absorbed by the plants, and they add a lot of humus to the soil. They are made in fields, so transportation is difficult for manures.
Manure adds nutrients to the soil without affecting its fertility. It does not damage crops and produces healthy plants. Fertilizers are chemicals which lower the fertility of the soil if used regularly. They also damage the crops and make them unhealthy for consumption.
The biggest disadvantage of using an organic fertilizer is that it may not contain primary nutrients like nitrogen, phosphorous or potassium, also known as NPK. Manure-based fertilizers contain these nutrients and are still considered organic.
Applying too much manure, at the wrong time, or improperly handling it in other ways releases nutrients into the air or into ground or surface waters. Thus, instead of nourishing crops, nutrients become pollutants. Excess nitrogen can leach through soil into groundwater.
Manure can contain human pathogens and through its use near fruits and vegetables, it can spread human pathogens to produce. Pathogens harmful to humans that are often found in manure include: pathogenic E. coli, Salmonella, and Listeria monocytogenes.
The advantages of using farmyard manure are that it's readily available, cheap, and easy to use because it's hard to overuse it. The disadvantages are that it has to be transported, doesn't smell too good, and requires consistent levels of certain organisms in the soil to break it down.
Don't Use Fresh Manure
If the manure is from a plant-eating animal, it is probably also full of weed seeds, which will not be inhibited from sprouting. If you still want to make use of fresh manure, don't apply it after your garden has been planted.
Animal manure applications can increase soil organic matter in medium / long term application periods. Consequently, manure contributes to reducing soil bulk density and compaction, as well as increasing soil aggregate stability, water infiltration and retention.
Among the major environmental impacts may be contamination of soil, water, and air by nutrients, organic carbon (C), heavy metals, and pathogens, as well as air contamination by particulate matters, noxious gases, and pathogens.
Livestock waste (manure) generates significant air and water quality issues in the form of methane and pathogens emissions as well as nutrient runoff to water bodies, which ultimately leads to eutrophication, algal blooms, and hypoxia [1, 2].
Animal manure may also carry pathogens that can present dangers to human health. cause of water quality impairment in streams, rivers, and estuaries. There are more than 150 organisms that can spread infection from animals to humans. Many of those can be found in animal feces and urine.
Drawbacks of composting by-products are cost for site preparation and equipment, the lengthy treatment period, targeting final use of compost product, and environmental issues such as odors and dust. Some investment in equipment and site preparation is required or recommended.
Manure organic matter contributes to improved soil structure, resulting in improved water infiltration and greater water-holding capacity leading to decreased crop water stress, soil erosion, and increased nutrient retention.
The use of manure in gardening can loosen compacted soil, increase carbon in the soil, and reduce surface runoff and leaching all while providing nutrients that your plants need. While this option is great, it is important to be aware of the potential carry over of herbicides in manure from grazing animals.
The primary factors that affect nutrient composition of manure are livestock type, stage of growth and feeding practices (all of which determine nutrient excretion rates) as well as the amount of bedding or water added to the manure, type of manure storage, time that the manure spends in storage and weather conditions.
Bacteria: There are several bacterial pathogens shed in livestock manure capable of causing disease in humans, including the common food-borne pathogens Escherichia coli O157:H7, Salmonella, Listeria, and Clostridium.
Manure might also increase carbon in soils as these materials have high carbon content. However, organic matter in manure might also be easily degraded due to its high nitrogen content or its low carbon-to-nitrogen ratio.
Manure that is piled and left alone will decompose slowly. This can take three to four months if conditions are ideal. It can take a year or more if the starting material contains a wide carbon:nitrogen ratio (as is the case when manure contains wood chips).