scholarly journals Effects of Phosphorus Fertilization on Productivity of Intensively Managed Grasses Under Humid Tropical Conditions in Puerto Rico

1969 ◽  
Vol 48 (3) ◽  
pp. 236-242
Author(s):  
Jacinto Figarella ◽  
José Vicente-Chandler ◽  
Servando Silva ◽  
Rubén Caro-Costas
Keyword(s):  
Puerto Rico ◽  
Phosphorus Content ◽  
Soil Phosphorus ◽  
The Other ◽  
Clay Soils ◽  
Phosphorus Fertilization ◽  
Humid Region ◽  
Tropical Conditions ◽  
Intensively Managed ◽  
Available Soil Phosphorus

The effects of phosphorus applications on yields and phosphorus content of otherwise well-fertilized tropical grasses growing on three typical soils of the Humid Region of Puerto Rico were determined. Napier grass responded strongly in yield to applications of 150 pounds of P2O5 per acre yearly on both Múcara and Catalina clay soils at Orocovis. The phosphorus content of the forage increased with applications of up to 300 pounds of P2O5 per acre yearly on both soils. On the other hand, Napier, Guinea, and Pangola grasses, growing on a Fajardo clay formerly in moderately fertilized sugarcane for many years, did not respond in yield or phosphorus content to applications of phosphorus over a 5-year period. Various methods of determining "available" soil phosphorus did not give satisfactory results with these soils.

THE INFLUENCE OF VARIETY, SOIL TEMPERATURE, AND PHOSPHORUS FERTILIZER ON YIELD AND PHOSPHORUS UPTAKE BY ALFALFA

1963 ◽  
Vol 43 (3) ◽  
pp. 355-360 ◽  
Author(s):  
M. Levesque ◽  
J. W. Ketcheson
Keyword(s):  
Soil Temperature ◽  
Dry Matter ◽  
Phosphorus Content ◽  
Soil Phosphorus ◽  
Phosphorus Uptake ◽  
Growth Period ◽  
Yield Potential ◽  
Phosphorus Fertilization ◽  
Maximum Value ◽  
Phosphorus Application

Du Puits and Ladak varieties of alfalfa were grown for 10 weeks in the greenhouse on soil-sand media controlled at temperatures of 10°, 18°, and 26 °C. P32-tagged superphosphate was applied at rates of 10 and 80 p.p.m. phosphorus, respectively. Dry matter yields and phosphorus content of the tissue was determined at the end of the growth period. Increasing soil temperature from 10° to 26 °C. caused corresponding increases in total phosphorus uptake as a result of an increase in dry matter yields as well as an increase in the percentage of phosphorus in the plant tissue. Ladak exhibited the higher yield potential although Du Puits was less affected by low soil temperature conditions and appeared capable of making better use of soil phosphorus. With the higher phosphorus application, the root-top ratio for Du Puits was greater than that for Ladak, and the maximum value for this ratio occurred at 18 °C. for each variety. P32 activity measured in the tissue indicated that soil temperature was critical in terms of phosphorus fertilization in the 4- and 6-week stages of growth.

scholarly journals Changes in Viability and Microflora of Soybean Seeds Stored under Various Conditions in Puerto Rico

1969 ◽  
Vol 62 (3) ◽  
pp. 255-264
Author(s):  
F. D. Tenne ◽  
E. J. Ravalo ◽  
J. B. Sinclair ◽  
E. D. Rodda
Keyword(s):  
Puerto Rico ◽  
Initial Moisture Content ◽  
The Other ◽  
Soybean Seeds ◽  
University Of Puerto Rico ◽  
Concomitant Increase ◽  
Tropical Conditions ◽  
Storage Location ◽  
The University ◽  
Main Effects

Woodworth soybean (Glycine max) seed lots were stored under tropical conditions at two locations of the University of Puerto Rico, in four types of containers at three moisture levels, arranged in a completely randomized factorial design. Germination overall factors decreased with time. Germin ation decreased with increased length of storage and was accompanied by a concomitant increase in the occurrence of Bacillus subtilis. After 9 mo, the seeds with an initial moisture content (dry basis) of 8.6% had a higher germination and lower occurrence of seed-borne microorganisms than those stored with 10.7% and 12.5%. Seeds stored in 200-g sealed food cans main tained germination longer than those stored in nonsealed cans with a plastic lining, plastic-lined fertil izer bags, or in cloth bags. Seeds stored in cloth bags had a greater incidence of B. subtilis than those from the other storage containers. Whether or not th ere were significant differences between storage location for any main effects or interactions depended upon the parameter measured.

scholarly journals Effect of Fertilization on Yields of Three Varieties of Rice at Two Locations in Puerto Rico

1969 ◽  
Vol 59 (1) ◽  
pp. 1-4
Author(s):  
Carmen T. Ramírez ◽  
Fernando Abruña ◽  
José Lozano ◽  
José Vicente-Chandler
Keyword(s):  
Puerto Rico ◽  
Minor Element ◽  
Phosphorus Fertilization ◽  
Irrigated Rice ◽  
Intensively Managed ◽  
The Tropics

Intensively managed irrigated rice of 3 varieties on a Vertisol typical of large areas in the tropics responded strongly to the application of 200 pounds of nitrogen per acre but not to phosphorus fertilization. Bluebonnet and Chontalpa varieties responded to the application of 200 pounds of potassium per acre, the Sinaloa variety to 300 pounds. All varieties responded strongly to the application of 40 pounds per acre of a complete minor element mixture.

scholarly journals Forage Yield of Five Grasses Under Intensive Grazing Management in the Humid Region of Puerto Rico

1969 ◽  
Vol 64 (3) ◽  
pp. 259-263
Author(s):  
Edmundo Rivera ◽  
José Rodríguez
Keyword(s):  
Puerto Rico ◽  
Large Scale ◽  
Forage Yield ◽  
Grazing Management ◽  
Yield Potential ◽  
Experimental Plot ◽  
Forage Grasses ◽  
Humid Region ◽  
Second Year ◽  
Intensively Managed

Three grasses on intensively managed and grazed 10 x 10 m plots produced statistically similar yields of dry forage over a 3-year period expressed in kg/ha/yr as follows: Stargrass—12,445; Coast Cross #1—12,285; and Hemarthria PI 299995—13,685. Hemarthria PI 299994 produced significantly higher yields—15,370 kg/ha/yr. Cynodon plectostachyus, on the other hand, did not tolerate intensive grazing and produced only 4,695 kg/ha during the second year. Yields of Star and Hemarthria PI 299995 were comparable to yields obtained in a large scale grazing experiment nearby, which confirmed the validity of the small experimental plot technique in determining yield potential of grazed forage grasses.

scholarly journals The influence of Some Soil and Climatic Factors on Sapogenin Yields of Dioscorea

1969 ◽  
Vol 51 (3) ◽  
pp. 260-265
Author(s):  
Franklin W. Martin ◽  
Herminio Delpín
Keyword(s):  
Puerto Rico ◽  
Plant Growth ◽  
Tuber Yield ◽  
Climatic Factors ◽  
The Other ◽  
Clay Soils ◽  
Stem Cuttings ◽  
Controlled Experiments ◽  
Wide Range ◽  
Dioscorea Species

Plants of two sapogenin-bearing Dioscorea species propagated by two different techniques, were tested at different locations in Puerto Rico over a 3-year period. In an experiment at Mayagüez plants grew best in a loose, well-drained soil, planted on flat beds rather than ridges, and without the addition of organic material (cachaza). In plots at Isabela, Corozal, and Adjuntas sapogenin yields were higher in the Isabela loam than in the heavier clay soils at the other locations. Plants propagated from stem cuttings gave better results in D. floribunda plantings; propagations from tuber pieces gave better results with D. composita. In these trials the propagation method and the effects of climate and soil influenced plant growth and tuber yields, but had little effect on the percentage of sapogenin developed in the tubers. Location effects on total sapogenin production resulted in most cases from differences in tuber yield, rather than in percentage sapogenin. These were the largest controlled experiments conducted with sapogenin-bearing species in Puerto Rico. Although these tests indicate that they are satisfactorily adapted to a wide range of conditions, it is clear that best yields are obtained in good, well-drained soils. Sapogenin yields were sufficiently high to be commercially valuable in all locations tested.

scholarly journals Some Effects of Calcium and Phosphorus Fertilization on the Yield and Composition of a Tropical Kudzu-Grass Pasture

1969 ◽  
Vol 41 (4) ◽  
pp. 231-235
Author(s):  
Fernando Abruña ◽  
Jacinto Figarella
Keyword(s):  
Puerto Rico ◽  
Protein Content ◽  
Phosphorus Content ◽  
Acid Soil ◽  
Acid Soils ◽  
Calcium Content ◽  
Mountain Region ◽  
Phosphorus Fertilization ◽  
Guinea Grass ◽  
Composite Samples

A tropical kudzu-molasses grass-Guinea grass pasture mixture growing on a deep, red, acid soil in the Mountain Region of Puerto Rico yielded an average of 12,938 pounds of dry forage per acre yearly with a crude-protein content averaging 8.5 percent, a calcium content of 0.56, and a phosphorus content of 0.26 percent. Liming increased the yield and protein content of tropical kudzu, but did not appreciably affect its calcium or phosphorus content. Liming did not affect the yield, or the protein, calcium, or phosphorus contents of the grasses. Applications of phosphorus had no apparent effect on the yield, or the protein or calcium contents of the forages. The application of 45 pounds of phosphorus per acre yearly, however, increased the phosphorus content of composite samples of the grasses over all yield periods, but not that of tropical kudzu. The results of this experiment suggest the desirability of making light applications of lime and phosphorus to kudzu-grass pastures growing on red, acid soils in the Mountain Region of Puerto Rico.

scholarly journals Efecto De La Fertilizacion Fosforo Azufrada Sobre El Sistema Radical Y El Rendimiento De Soja En El Centro De Argentina

2016 ◽  
Vol 12 (27) ◽  
pp. 18
Author(s):  
M. D. Bongiovanni ◽  
G. A. Cerioni ◽  
A. Gonzalez Giorgi ◽  
E. Dobla
Keyword(s):  
Root Length Density ◽  
Soil Phosphorus ◽  
Primary Root ◽  
Dry Weight ◽  
Root Diameter ◽  
Control Treatment ◽  
Phosphorus Fertilization ◽  
Single Superphosphate ◽  
El Sistema ◽  
Available Soil Phosphorus

The objective was to evaluate grain the effect of sulfur and phosphorus fertilization on root growth, nodules and soybean yield. The test was performed at 25 km west of Coronel Baigorria department Río Cuarto; Córdoba, Argentina on a Haplustol entic from the series Alpa Corral. Treatments applied were made different doses of single superphosphate (21% P205 y 12% de S).TO: control treatment, no fertilizerT1: 5,5 Kg ha-1de P y 7,2 Kg ha-1de S; T2: 10,9 Kg ha-1de P y 14,4 Kg ha-1 de S y T3: 16,48 Kg ha-1 de P y 21 Kg ha-1.During crop cycle the following observations and measurements: emerged seedlings, root dry weight, number of nodules, primary root diameter, root length density (DLR), and determine harvest, crop yield (kg/ha) and levels of available soil phosphorus at harvest. In this research project the application of phosphorus-sulfur fertilizer produced changes in soybean root system, by increasing dry weight of roots, generating lateral growth, improving the symbiosis with nitrogen-fixing bacteria which result in more number of nodules per root. Fertilization also modified rooting patterns increasing DLR in most fertilizer treatments, effects that resulted in an increase in soybeans yield.

scholarly journals Effect of Heavy Rates of Fertilization on Beef Production and Carrying Capacity of Napier Grass Pastures over 5 Consecutive Years of Grazing Under Humid Tropical Conditions

1969 ◽  
Vol 56 (3) ◽  
pp. 223-227
Author(s):  
Rubén Caro-Costas ◽  
José Vicente-Chandler
Keyword(s):  
Puerto Rico ◽  
Carrying Capacity ◽  
Napier Grass ◽  
Mountain Region ◽  
Beef Production ◽  
Fertilizer Rate ◽  
Tropical Conditions ◽  
Growing Cattle ◽  
Intensively Managed ◽  
Steep Slopes

Intensively managed Napier grass pastures on steep slopes in the humid mountain region of Puerto Rico grazed by young growing cattle over a 5-year period, produced an average of 947,1,281 and 1,582 pounds of gain in weight per acre yearly when fertilized annually with 1,600, 2,800 and 4,000 pounds of 14-4-10 fertilizer per acre, respectively. The pastures carried the equivalent of 2.22-, 2.89- and 3.58 six-hundred-pound steers per acre throughout the year and produced 6,890, 8,960 and 11,100 pounds of total digestible nutrients per acre yearly at the 1,600-, 2,800- and 4,000- pound fertilizer levels, respectively. Daily gains per head were not affected by level of fertilization, and averaged 1.31 pounds. At the 4,000-pound fertilizer rate the pastures maintained a minimum of 3 head per acre and produced 1,582 of liveweight worth about $475 at current prices or $315 above fertilizer costs.

Improved Plant Diversity as a Strategy to Increase Available Soil Phosphorus

2019 ◽  
Vol 103 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Carlos Crusciol ◽  
João Rigon ◽  
Juliano Calonego ◽  
Rogério Soratto
Keyword(s):  
Crop Yields ◽  
Soil Phosphorus ◽  
Cropping System ◽  
P Availability ◽  
P Fractions ◽  
Crop Species ◽  
Soil P ◽  
Residue Decomposition ◽  
Available Soil Phosphorus ◽  
Crop Residue Decomposition

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.

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