3rd b 2 historical development in soil fertility and plant nutrition
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Historical development in soil fertility and plant nutrition
The period in the development of the human raceduring which man began the cultivation of plantsmarks the dawn of agricultureThe exact time is not known, but it was certainly several thousands of years BCUntil then, man was nomadic in his habits
In all ages the growth of plants has interestedthoughtful manThe mystery of the change of an apparentlylifeless seed to a vigorous growing plant neverloses its freshness, and constitutes, indeed, nosmall part of the charm of gardeningThe economic problems are of vitalimportance, and become more and moreurgent as time goes on and populationincreases and their needs become morecomplex
We know now the facts about the needs ofessential nutrients and other factors of plantgrowthThese facts are the result of a few hundredyears of thinking and researchWe thus need to know how this subjectdeveloped historically
Ancient RecordsAgriculture started when man became more of a settler than of a wanderer. Families, clans, and villages developed and the skill of agriculture developed.Mesopotamia situated between Tigris and Euphrates in Iraq- very early civilizationWritings dating back to 2500 BC mention the fertility of the landIt is recorded that the yield of Barley was 86x 300x, i.e., for every unit of seed planted the harvested units were 86 to 300
Some 2000 years later (500 BC) Herodotus, the Greek historian- mentions the phenomenal yields obtained by the inhabitants of his landWell developed irrigation system and soils of high fertilityAround 300 BC- Theophrastus richness of the Tigris alluvium and stated that the water was allowed to remain on the land as long as possible so that large amount of silt may be depositedIn time man learned that certain soils would fail to produce satisfactory yield when cropped continuouslyThe practice of adding animal and vegetable manures to the soil to restore fertility probably developed from such observations but how and when is not known
Augeus a egendary king of Elis, had 3000 oxen in his stable which was not cleaned for 30 years.Augeus contracted Hercules to clean the stable out and agreed to give him 10% of the cattle in returnHercules is said to have accepted the task by turning the river Alpheus through the stable This carried away the accumulated filth and presumably deposited it on the adjacent land thus enriching the land.In the Greek epic poem The Odyssey (Homer ,900-700 BC) the manuring of vineyards by the father of Odysseus is mentioned.The manure heap, which would suggest its systematic collection that manuring was an agricultural practice in Greece during the 9 centuries BC
Xenophon (434-355 BC) observed that the estate has gone to ruin because someone didnt know it well to manure the land. And again . there is nothing so good as manureTheoprhastus (372-287 BC) recommended abundant manuring of thin soils but suggested that rich soils be manured sparingly.Bedding in the stall to absorb more of the urine and bulk and conserve it humus value of the manure would be increasedHe suggested that plants with high nutrient requirements also had a high water requirementThe truck gardens and olive groves around Athens were enriched by sewage from the cityA canal system was used, and there is evidence of device for regulating the flowIt is believed that sewage was sold to farmers.
The ancients also fertilized their vineyards and groves with water that contained dissolved manuresManures were classified according to their richness or concentration.Theophrastus listed the manures in the following order of decreasing value:
human> swine > goat > sheep > cow > oxen > horseLater, Varro, an early writer on Roman Agriculture, developed a similar list but rated bird and fowl manure as superior to human excrement:
bird + fowl > human>swine>goat>sheep>cow>oxen>horseArchilocus (ca. 700 BC) mentioned about the effect that dead bodies had on increasing the growth of crops.In Old Testament; in Omar Khayyam etc.
The value of green manuring crops, particularly legumes, was also soon recognised.Theophrastus noted that a bean crop (Vicia faba) was plowed under by the farmers of Thessaly and MacedoniaHe observed that even when thickly sown and large amounts of seeds were produced, the crop enriched the soilXenophon (ca. 400 BC) recommended spring ploughing because the land is more friable then and the grass turned up is long enough at that season to serve as manureCato (234-149 BC) suggested that poor vineyard land be interplanted with a crop of acimum. This crop was not allowed to go to seed and ir was turned under.He also said that the best leguminous plant for enriching the soil were field beans, lupines and vetch
Lupine was quite popular with the ancientsColumella listed numerous legume crops, including lupines, vetch, lentils, chick peas, clover, and alfalfa that were satisfactory for soil improvementVirgil (70-19 BC) advocated the application of legumesThe use of what might now be called mineral fertilizers or soil amendments was not entirely unknown to the ancientsTheophrastus suggested the mixing of different soils as means of remedying defects and adding heart to the soilThis practice may have been beneficial from several standpointsThe addition of fertile soils to infertile soil could lead to increased fertility, and the practice of mixing one soil with another may have provided better inoculation of legume seed in some fields
Again, the mixing of coarse textured soils with those of fine textured or vice versa may have caused an improvement in the water and air relations in the soils o0f the fields so treatedThe value of marl was also recognised. The early dwellers of Aegina dug up marl nd applied it to their landThe Romans even classified the various liming materials and recommended that one type be applied to grain and another type to meadowPliny (62-113): lime should be spread thinly on the ground and that one treatment was sufficient for many years, though not 50Columella also recommended the spreading of marl on a gravely soil and mixing of gravel with a dense calcareous soilThe value of wood ashes is recorded in the BibleBoth Xenophon and Virgil: burning of stubble to clear fields and destroy weeds
Cato: advice to the vine keeper to burn prunings on the spot and to plough in the ashes to enrich the soilPliny: use of lime from lime kilns was excellent for olive grovesColumella: suggested the spreading of ashes or lime on lowland soils to destroy acidityTheophrastus and Pliny: saltpetre (KNO3) as useful for fertilizing plantsTheophrastus reported the use of brine for palm treesEven as soil scientists of modern times have been searching for methods of predicting the fitness of soil for production of crops, so did the minds of the early agricultural philosophers and writers turn to such methodsVirgil: believed that soil that was blackish and fat under the deep pressed share, and whose mold is loose and crumbling is generally best for corn. He also wrote about soil characteristics now known as bulk density
Columella: measure the degree of acidity and salinity of soilsPliny: bitterness of soils might be detected by the presence of black and underground herbsMany of the early writers believed that the color of the soil was a criterion of its fertilityThe general idea was that black soils were fertile and light or grey soils infertileColumella disagreed with this view point: black marsh land soil infertile; light colored soil from desert area highly fertileHe felt that such factors as structure, texture and acidity were for better guides to an estimation of soil fertility
Much of the early writings regarding soil fertility consisted largely of descriptions of farm practicesThere seems to be little evidence of an experimental approach to farm problems, but many of these manuscripts do reflect a rather keen comprehension of certain of factors now known to affect plant growth.
Soil fertility during the 1st eighteenth century ADAfter the decline of Rome there were few contributions to the development of agriculture until the publication of Opus ruralium commodorum, a collection of local agricultural practices, by Pietro de Crescenzi (1230-1307) De crescenzi is referred to by some as the founder of modern agronomyHe suggested an increase in the rate of manuring over that is use at the timePalissy (1563) made the observation that ash content of plants represented the material they had removed from the soil
Around the beginning of the 17th century Francis Bacon (1561-1624) suggested that the principal nourishment of plants was water, the main purpose of the soil was to keep the plants erect and to protect them from heat and cold and that each plant drew from soil a substance unique for its own particular nourishmentBacon also maintained that continued production of the same type of plant on a soil would impoverish it for that particular species
Jan Baptiste van Helmont (1577-1644) a Flemish physician and chemist, reported the results of an experiment which he believed proved that water was the sole source of nutrient of plants200 lb soil + water; shielded soil to prevent dust and only rain or d.w was used. A willow shoot weighing 5lb was planted. The plant was grown for 5 years. After 5 years the tree that grew weighed 169 lbs 3 ozs. He could account for all but 2 ozs of the 200 lbs of soilAs he added only water so was the sole source of nutrientThe 2 ozs was attributed to experimental error.The work was done when nothing was known about mineral nutrition and photosynthesis
Van Helmonts work was repeated several years later by Robert Bo