Inagriculture, theyield is a measurement of the amount of acrop grown, or product such as wool, meat or milk produced, per unit area of land. Theseed ratio is another way of calculating yields.
.png)
Innovations, such as the use offertilizer, the creation of better farming tools, and new methods of farming and improvedcrop varieties have improved yields. The higher the yield and moreintensive use of the farmland, the higher the productivity and profitability of a farm; this increases the well-being of farming families. Surplus crops beyond the needs ofsubsistence agriculture can be sold or bartered. The more grain or fodder a farmer can produce, the more draft animals such ashorses andoxen could be supported and harnessed for labour and production ofmanure. Increased crop yields also means fewer hands are needed on farm, freeing them for industry andcommerce. This, in turn, led to the formation and growth of cities, which then translated into an increased demand for foodstuffs or other agricultural products.
The units by which the yield of a crop is usually measured today arekilograms perhectare orbushels peracre.
Long-term cereal yields in the United Kingdom were some 500 kg/ha in medieval times, jumping to 2000 kg/ha in the Industrial Revolution, and jumping again to 8000 kg/ha in theGreen Revolution.[1] Each technological advance increasing the crop yield also reduces the society'secological footprint.[citation needed]
Yields are related toagricultural productivity, but are not synonymous. Agricultural productivity is measured in money produced per unit of land, but yields are measured in the weight of the crop produced per unit of land. A farmer can invest a large amount of money to increase his yields by a few percent, for example with an extremely expensivefertilizer, but if that cost is so high that it does not produce a comparativereturn on investment, his profits decline, and the higher yield can mean a lower agricultural productivity in this case. A yield is a 'partial measure of productivity', because it may fail to accurately measure the actual productivity of the farming operation by not including the totality of the inputs.[2]
The seed multiplication ratio is the ratio between the investment in seed versus the yield. For example, if three grains areharvested for each grain seeded, the resulting multiplication ratio is 1:3, which is considered by someagronomists as the minimum required to sustain human life.[3] One of the three seeds must be set aside for the next planting season, the remaining two either consumed by the grower, or forlivestock feed. In parts of Europe the seed ratio during the 9th century was merely 1:2.5, in theLow Countries it improved to 1:14 with the introduction of thethree-field system ofcrop rotation around the 14th century.[4]
Seed multiplication ratio is variable, subject to several factors. Agricultural improvements can raise the ratio, and revisions were recommended in 2018 by the Indian Council of Agricultural Research.[5]
Alexander Mitscherlich studied crop yields in 1909[6] and articulated a "law of physiological relations".[7] It was compared to thelaw of diminishing returns in 1942, whenLiebig's law of the minimum and thelimiting factors ofFrederick Blackman were also noted:
The relation was reviewed by Hans Schneeberger in 2009.[9]
Ritchie, Hannah; Rosado, Pablo; Roser, Max (2022)."Crop yields".Our World in Data. Retrieved2024-04-20.
