The rice represents next to the wheat, the cultivated cereal more of the world, being consumed like the main food by half of the world-wide population, distribuída specially in the Asian continent. Year after year, its consumption comes the rice extending, being in Asia main the carbohydrate source and same of proteins, where the protein deficiency animal is elevated.

Numerous species of rice exist, but hardly two are cultivated: ORIZA SATIVAL And ORIZA GLABERRIMA. First, spread throughout the world, the second prisoner to the regions of Western Africa. In Asia there is a glutinous variety Lour, extensively cultivated with glutinous or consumed rice like associated delicate plate to other ingredients.

The origin of the rice is Asian, being pointed India and Indochina like the countries that gave origin him. Of it was spread there to the countries of tropical and subtropical area being today scattered by all the continents, but always we remember that 90% of the world-wide population are in Asia. The world-wide production of rice in 1970 was considered in 308.214.000 tons, being the cultivated area of 136.162.000 has.

Of that production 91% belong to Asia; in America paías that goes to the vanguard is Brazil, that as well occupies 8º place like world-wide producer according to the statistics of year 1970.
   
 

Table of concentration of micronutrients in the trunks of Rice in relation to the application of Zinc and Magnesium:
Treatment
Age of the plants (days)
Elements in dry matter p.p.m.
Fe.
Mn.
Ca.
B.
Zn.
1-NPK + Mn
32
688
640
18,4
12
12
2-NPK
585
261
13,7
23
8
3-NPK + Mn + Zn
688
418
13,7
21
108
4-NPK + Zn
805
148
15,7
20
67
1-NPK + Mn
54
1.153
434
27,8
25
21
2-NPK
1.566
272
24,7
23
15
3-NPK + Mn + Zn
856
228
18,3
18
53
4-NPK + Zn  
1.089
276
17,2
21
36
1-NPK + Mn
62
2.056
244
27,7
19
25
2-NPK  
1.927
291
22,0
23
16
3-NPK + Mn + Zn  
1.463
254
21,3
18
39
4-NPK + Zn  
1.618
272
21,0
18
29
1-NPK + Mn
99
1.669
651
29,4
30
28
2-NPK  
1.127
260
24,0
31
18
3-NPK + Mn + Zn  
896
323
22,4
24
26
4-NPK + Zn  
1.177
387
15,9
16
27
 

Conditions of the ground and nutricionales occurrences of the rice:
Conditions of the ground
Nutritional Problems
I) pH. very under (very acid grounds) Single with Sulphate: Iron toxicity

II)pH. under (acid grounds)
a) High in Active Iron:
1)Bajo in organic matter; phosphorus deficiency.
2) Stop in organic matter: phosphorus deficiency by Iron toxicity.
3) Iodine Stop: Iodine toxicity by phosphorus deficiency.
4) Magnesium Stop: magnesium toxicity.

b) Low in Active Iron and cations cambienates:
1) Low in potassium: Iron toxicity by potassium deficiency.
2) Low in bases and Siliceo with application of Sulphate: imbalance of Nutrients by H2S toxicity.

III) High pH (alkaline grounds):

1) Calcium High: Zinc and Iron phosphorus deficiency.
2) High in Calcium and under Potassium: potassium deficiency by excess of calcium.
3) Sodium High: Iron salinity, deficiency and Boron toxicity.
 


SOYBEAN, (Glycine Max (l) Merril). The use of the soybean, like human food, goes back to centuries and has its origin in China. References on this plant were found in Li-yu-ying and Grandvoinnet (1912) in a work written by She-Non, in the year 3000 A.C. The culture of the soybean was so important in old China to such point to take itself in the base of the food of its "grano town and considered sagrado".

Per millenia, its use was restricted in that country, until in century XVII of ours it was, began to scatter by other regions of Asia. In Europe, the soybean became well-known as of 1739, when it was planted in the Botanical Garden of Paris.

In 1804 the first reference on its behavior in America was made (the U.S.A.), soon in America of the South (Brazil). The east of Western China is mentioned like "la mother country of soja". Recent works (Nagata 1960) taking in account the wild grain distribution and species, located to the North and Central regions of Continental China, like the center of the origin of the soybean.

This is a herbaceous, annual plant, with a vegetative cycle approximately of 130 to 150 days for the cultivated varieties. In normal conditions its height is near 100/150cm in the maturation. The soybean stands out by its sensitivity to the development during the day, being important factor the period of absence of light in the formation of the floral buds.

Plant of short days is considered, blooming when the days begin to become short, being this fact of excellent importance at the time of the plant.

In spite of being original plant of tempered climate regions, the soybean adapts well in an ample extension with other climates.

Thus their acclimated varieties develop and produce very well in conditions of subtropical and tropical climate. The optimal average temperatures for the best unfolding of the soybean are between 20 and 35ºC. It raises or of low already they appear physiological disturbances, specially to which one talks about to flowering and formation of modules in the roots. Annual pluviométricas precipitations of 700 to 1200mm distributed the necessities of the water well. Within the family of the micronutrients, the ZINC, acts a as in small amounts.

The ZINC deficiency appears with leaves of yellow brown coloration, not letting develop the same ones to normal size. The symptoms are but severe in conditions humedas and frias, disappearing with heat. The presence of remarkable symptoms but happens in the old leaves but. Excess of calcium can diminish the ZINC availability and installments also phosphatized heavy can reduce the ZINC absorption.

Often the leaves have been very small, with groups of the same ones (rosettes). They are symptoms estoa that can be corrected perfectly applying dose that we detailed:
Applied in form to foliar diluído to 3% or 10 to 15kg xs it has. Dusting the ground once plowed the field.
   
 


The Maize, Zea May L, paises is one of the main cultures in many, competing with the wheat, rice and oats in the world-wide cereal production. Original of America. It occupies near 25% of the cultivated area of the U.S.A., its main producer, person in charge of 50% of the world-wide total. They follow in importance order the U.R.S.S., Chian, Brazil, Argentina, Yugoeslavia, Italy and others paises.

For the Western civilization history began in 1942 after discovered America. Cristóbal Columbus when disembarking in the island of Cuba, encontro in its interior a plant to which the native ones called "mahis" with which they made a flour species.

Stranger in the old world, the maiz one already was cultivated towards centuries in the Ameritas, being found in the tombs of years Incas seeds of those precious gramineas. Of America the Spaniards took it to Europe in century XIV, of where I emigrate for smaller Asia, Africa, East, etc. Spreading everywhere. At the moment one is endorsed by all the continents occupying in some regions positions of great economic expression.

The production and the consumption have increased in some countries thanks to the great unfolding that took the sector from technology of foods, allowing through industrialization a better advantage of the grain. This which he was used directly and almost exclusively in the feeding animal, it happened to be used in the product obtaining diverse of great use in the modern life, as: Starch, Dextrin, Glucose, crude and nutritional Oil, Bran, Proteinic, Antibiotic, etc. Those products are used in the manufacture of drinks, woven, dry batteries, paper, explosives, tanneries, smelting, minerals and industries of the plastic and petroleum.

The maize or Zea Mays, is a herbaceous monocotileidonea annual monóica pertaining to TRIBO MAYDAE, sub family PARNICOIDEAE and family of the gramíneas. Its height varies between two and three meters.
The clomáticas conditions demanded by the maize are varied possible. Its geographic distribution in spite of being tropical culture, is between latitudes 58º N. (Canada - U.R.S.S.) until South 40º (Argentina) preferring climates that pesenta during its cycle temperatures not very low (20-22ºC) and sufficient humidity succumbing by ice cream effect. One develops bad to temperatures to low 19,5ºC, in where the nights frias have temperatures of 12,8ºC.

Upon the average temperature diari to of 26ºC, the blossoming and the maturation is fast. As case curiosodiremos that are different varieties from maize in localities of low altitude (region of the Caspian Sea) under the level of the sea and until but of 3600mts of height in Peruvian the $andes. They support regions with annual precipitation of 250mm until upon 5000mm being that demands minimo of 200m during the summer, for production without irrigation.
   
 


Innumerable investigations have become and great I number of data with respect to the mineral exigencies of the maiz. This it requires for its normal unfolding, mineral elements that on the point of view of the vegetal nutrition, it has been divided in 3 groups:

1º Group:
Macronutrientes: considered essential in the plants, they are consituidos by the following elements: N-P-K Ca-Mg-S.

2º Group:
Micronutrientes: they are so essential in the plants as first, but thus they are denominated because they are absorbed in very small amounts and they are: Zn-Cn-Fc-Mn-B-C1 and Mo.

3º Group:
Accessory Elements: they are considered nonessential, are found frequently in vegetal weaves, appreciable amount. Performing in the maize more nonvital functions of importance; they are they: If, Na, His, Co, Pb, Ag, Cr, Mr. and Ba.

Many samples of maiz normally are collected in order to chemically determine the concentration of nutrients of their diverse parts and different colors. Such studies provide a better nonsingle knowledge of the amounts of demanded elements po the plant like also of the times of the cycle in which more they are solicitd. Known it is that the macronutrients are used in the ground treatments, but our investigations arrived beyond that point and was completely the one that worries the micronutrient to us: within same main the Zn.

The Zn is a micronutrient very demanded by him maize studying the relative capacity of near 26 plants the Zinc absorption of the ground classifying itself in three groups: , little the moderately and very able in agreement with greater or smaller facility of absorption of element of the ground. Asi the group of the little able ones is the plants that are not able to retire sufficient amounts of Zinc of the ground. In this group the maiz was placed, next to poroto, soybean and others.

The lack of Zinc in the maiz causes a series of deficiencies, pronouncing itself, in diverse parts as symptom to foliar in form of a clorosis. Such difference happens in diverse parts of the world and the U.S.A. where she is well-known with the name of "WHITR BUD", that deficiency appears in ground or alkaline ground general that received many additions of calcáreos, being able in the meantime, to happen in acid and poor grounds. The symptoms develop after 2º to 3º week after the germination. The aparecimiento of a clorosis in the leaves occurs then but old and they are pronounced through 2 yellow strips placed one to each side of the main nerve.

The clorosis begins in the base of the leaves, usually the edges of the main nerve remain green. In those cases of severe deficiency, the clorosis happens to pale yellow coloration and the symptoms also reach to the new daughters but. The leaves but severely get to die. There are ocaciones in which they can be noticed in the base of the new leaves but. Other times in the leaves appear almost white, with green coloration, as soon as a strip throughout the main nerve. As the plants become but old the symptoms tend to disappear. The old but attacked leaves die and fall, but new they happen to show the symptoms in the internervous zone.

Also it has been possible to verify that the Zinc deficiency can show a second alternate green and constituted yellow ray symptom in the internervous space.

The influence of the clorosis on the production can be considered in function of its intensity. Despite the deficient plants they will recover, and its sera production accompanied due to the shortening by the internadios that accompanies the foliares symptoms with pulverizations by solutions to 0.05% of Zinc sulphate, they will correct the Zinc deficiencies in the maize. In the devoid Zinc treatments the tenor of the 20 leaves was of 10 to p.p.m and those that received Zinc, upon the 50 p.p.m.

In the several studies also made it was verified that the faltante Zinc factor in grounds must to that the same one was removed by earthworks, thing that is common in irrigated lands. Also it is admitted like corrective treatment of the lack of Zinc. The aspersion on the plant of a Zinc Sulphate solution to 5% neutralized with Ca. (OH)2 to 25% or adding Zinc Sulphate next to other fertilizers in a 10 dose from 5 to Kgrs./Ha.