Effects of Age at Harvest and Fertilizer Application on the Yield, Available Carbohydrates and Hydrocyanic Acid Content of Cassava (Manihot palmata Pohl)

1977 ◽  
Vol 88 (3) ◽  
pp. 679-681
Author(s):  
G. O. Obigbesan ◽  
A. O. Ketiku ◽  
A. A. Fayemi

SUMMARYExperiments were carried out over two growing seasons to find out the effects of fertilizer application and age at harvest on the yield, available carbohydrates and hydrocyanic acid content of Manihot palmata.Fertilizers were applied at the following rates: 0–0–0; 45–45–0; 45–45–45; 45–45–67, and 45–45–90 kg/ha of nitrogen, phosphorus and potassium respectively. Harvests were at 9 and 15 months after planting. Application of nitrogen and phosphorus resulted in significant yield increases. Fertilizer application had no significant effect on the hydrocyanic acid content of the tubers. Harvesting at 15 months gave more than double the tuber yields and a higher percentage of hydrocyanic acid than harvesting at 9 months. It is, therefore, desirable to use efficient methods of processing the tubers harvested at 15 months to obtain safe products for industrial and nutritional uses.

Author(s):  
P.Yu. Latartsev ◽  
◽  
O.I. Antonova ◽  

The study of the content and removal of nitrogen, phosphorus and potassium by linseed flax plants of the oilseed variety Severniy showed that more nitrogen and phosphorus accumulated in seeds, and potassium -in straw. The average content levels in seeds were as follow-ing: N -4.79%, P2O5 -0.79%, K2O -1.05% as compared to respective levels in straw: 0.64%, 0.1% and 1.73%. When applying fertilizers, the content of all nutrients in the straw decreases, and in the seeds it mainly remains at the con-trol level. Due to the higher crop yields in all fertilized vari-ants, the removal of phosphorus and potassium exceeds the control; and nitrogen removal –in the variants with a higher rate of nitrogen application. With seeds, an average of 87-87.8% of nitrogen and phosphorus and 37.3% of potassium from the total removal is removed from the field. Increased rate of nitrogen application contributes to greater consumption of not only nitrogen but also phosphorus and potassium. The rates of nitrogen application in the experi-ments do not compensate for its yield removal with seeds; that requires increased nitrogen application against the background of phosphorus-containing fertilizers.


Author(s):  
Kwadwo Gyasi Santo ◽  
Joseph Sarkodie-Addo

Studies were carried out at Offinso in the Ashanti Region of Ghana to assess root quality of cassava grown with application of poultry manure and NPK 15-15-15 and NPK 23-10-10 fertilizers. The experimental design was a 2 x 6 factorial, arranged in a Randomized Complete Block Design (RCBD) with three replications. The treatments consisted of two cassava varieties in combination with five inorganic and/or organic fertilizer formulations and a control with no fertilizer. The parameters measured were starch content, poundability, nitrogen, phosphorus and potassium contents of cassava roots. The data collected were subjected to analysis of variance using the Genstat Statistical package. The results of the study indicated that Bankyehemaa produced higher starch content (29.86%) than the Nkabom variety. Fertilizer application increased starch content with the combined application of poultry manure and NPK 23-10-10 treatment recording the highest treatment effect (30.40%). Both the organic and inorganic fertilizers applied increased starch content of cassava roots. Poundability was not also affected by both variety and fertilizer application. However, roots treated with NPK 15-15-15 only and poultry manure alone were very poundable (3.0). Variety significantly affected only nitrogen and phosphorus contents of cassava roots. Bankyehemaa had higher content (0.72%) of nitrogen than Nkabom, while Nkabom recorded higher content (1.05%) of phosphorus than Bankyehemaa. Generally, application of fertilizer significantly affected root contents of nitrogen, phosphorus and potassium. However, potassium and phosphorus contents were reduced by the organic fertilizer (poultry manure). The NPK 15-15-15 treatment produced higher potassium (9.37%) and phosphorus (1.36%) contents of roots than the other treatments. The highest nitrogen content of roots (0.78%) was observed in the combined application of poultry manure and NPK 23-10-10 treatment.


Nematology ◽  
2002 ◽  
Vol 4 (4) ◽  
pp. 527-539 ◽  
Author(s):  
Sven Jonasson ◽  
Inger Schmidt ◽  
Anders Michelsen ◽  
Liliane Ruess

AbstractNutrient availability is a major constraint on plant production and carbon storage in arctic ecosystems but knowledge on the decomposer food web interactions and their effect on nutrient cycling is scarce. We manipulated the soil food web at two contrasting subarctic sites, a low altitude heath and a high altitude fell-field. The influx of nutrients and energy in the soil was increased by addition of fertiliser nitrogen, phosphorus and potassium and of labile carbon (sugar). In addition, two bactericides (penicillin and streptomycin) and a fungicide (benomyl) were applied to manipulate the bacterial and fungal component of the soil. Experiments were carried out in a factorial design with repeated additions over four growing seasons. The present study investigated the nematode fauna and the effects of the manipulations on the abundance of nematode species. Fertilisation resulted in an increase of general opportunists, especially Aphelenchoides. Application of carbon or bactericides had only minor impact on the nematode community. In contrast, the fungicide was very toxic to non-target organisms and greatly reduced the abundance of most nematode species, although Acrobeloides buetschlii showed tolerance and greatly increased in number. At both sites, Eudorylaimus was most affected by the treatments. Generally the manipulations performed resulted in a significant increase in stress tolerant or competitive dominant nematode species.


1976 ◽  
Vol 56 (1) ◽  
pp. 127-131 ◽  
Author(s):  
J. A. CUTCLIFFE ◽  
D. C. MUNRO

The effects of nitrogen, phosphorus, and potassium on the yield and maturity of cauliflower (Brassica oleracea L. ssp. botrytis cv. Snowball Y) were investigated at a total of nine locations during three successive cropping seasons. Yields were substantially increased at most locations by applications of nitrogen and phosphorus but were only slightly affected by applied potassium. Maturity was slightly delayed by a lack of phosphorus. Maximum yields were generally obtained where N was applied at 112–224 kg/ha, P at 49–98 kg/ha, and K at 93 kg/ha.


1973 ◽  
Vol 53 (2) ◽  
pp. 357-361 ◽  
Author(s):  
J. A. CUTCLIFFE ◽  
D. C. MUNRO

The effects of nitrogen, phosphorus, and potassium on the yield and shape of rutabagas (Brassica napobrassica Mill., cult York) were investigated at three locations each year during three successive cropping seasons. Total and marketable yields were increased at most locations by applications of nitrogen and phosphorus, but applied potassium increased yields at only three locations. For maximum yields, rates of 90–112 kg/ha of N and 49–130 kg/ha of P were necessary. Where soil P levels were low, yield increases from applied N were obtained only when accompanied by adequate phosphorus. The ratio of the equatorial/polar diameters of the roots was increased by added N, and to a lesser extent, by applied P and K.


1972 ◽  
Vol 79 (3) ◽  
pp. 391-396 ◽  
Author(s):  
Akinola A. Agboola

SUMMARYStudies of the relationship between yield and content of N, P and K in the ear leaf of eight varieties of Nigerian maize, tested for three growing seasons, indicated that the varieties have different critical nutrient levels, although the values obtained for individual varieties were not significantly different from the pooled average critical level for any of the nutrients. The critical levels ranged from 2·85 to 3·19% N, 0·20 to 0·27% P and 2·06 to 2·60% K, while their pooled averages were 3·10% N, 0·23% P and 2·44% K.High ear leaf nutrient content was not a guarantee of high grain yield, and ear leaf nutrient values of low-yielding varieties were similar to those of the high-yielding varieties.


2014 ◽  
Vol 17 (1) ◽  
pp. 79
Author(s):  
K.T. Zhantasov ◽  
Z.U. Myrhalykov ◽  
S.M. Moldabekov ◽  
M.K. Zhantasov ◽  
B.T. Omarov ◽  
...  

Analysis of modern scientific literature and patents has shown the absence of acid-free production technology of a mechanically activated multicomponent mineral fertilizer containing water-holding substances. Experimental researches connecting with mechanochemical activation and physicochemical properties of Karatau phosphorites prove a possibility of development of a new multicomponent mineral fertilizer. Application of inorganic and organic activators considerably improves qualities of fertilizers because the developed fertilizer mixtures contain nitrogen, phosphorus, potassium, humate and microelements. The suggested technology intends to use wastes of coal mining that leads to presence of humates and microelements in the end product. It was determined, that content of total nitrogen, phosphorus and potassium depends on a form of nitrogen-phosphorus-potassium-containing substances. The given article contains data of researches connecting with use of multicomponent mineral fertilizers in field conditions for cotton cultivation on irrigated light sierozems consisting of soil-forming rocks of loess and loess-type clay loams. The research results show the increase of soil’s fertility and cotton’s productivity. Studying of agronomic efficiency of the new kinds of mechanically activated multicomponent mineral fertilizers at the cultivation of a bean-cereal mixture has been carried out in the Negorelsk experimental nursery-garden of the Belarus State Technical University on a sod-podzol sandy-loam soil and has shown the essential influence on productivity and quality of the bean-cereal mixture. The researches fulfilled on a sod-podzol sandy-loam soil have revealed the essential increase of key indicators of feed productivity. Application of the mineral fertilizers has promoted increase of nitrogen, phosphorus and potassium content in green plants. In so doing content of calcium and magnesium in green mass depends from quantity of the fertilizer used to a smaller extent. An essential difference of crop capacity and feed productivity indicators depending on forms of the applied mineral fertilizers has not been found.


2008 ◽  
pp. 93-99
Author(s):  
Róbert Víg ◽  
Attila Dobos ◽  
Zoltán Pongrácz

The soil fertility was degraded as a result of unreasonable tillage, therefore the application of site-specific nutrient replacement is necessary. It is essential for the application of precision fertilization to know the location, extension, soil properties and nutrient-supply of the different soil types ofcultivated areas.We collected soil samples from 580 hectares of land in 2006. Soil samples were collected from every 5 ha in 30 and 60 cm depths during Spring from 20.05.2006 to 12.06.2006 and again in Autumn from 09.19.2006 to 02.10.2006. Soil samples were analysed at the Department of Agricultural Chemistry and Soil Science of DE-ATC.The two examined soils are slightly calcareous, weakly saline, poor in zinc. The calcareous chernozem soil is slightly acid, the content of humus, nitrogen, phosphorus and potassium is medium in this soil. The meadow chernozem soil is slightly alkaline, and properly supplied with humus and potassium, and middling supplied with nitrogen and phosphorus. The meadow chernozem soil is more heterogenous in soil plasticity, lime, saline, nitrogen phosphorus and potassium content and less heterogenous in pH and zinc content than the calcareous chernozem soil.Standard deviation of measured values in pH, soil plasticity, humus and nitrogen content significantly differ between the examined soil types. The soil plasticity, pH, humus, nitrogen and zinc content significantly differ among calcareous chernozem soil and meadow chernozem soil, but the difference in phosphorus content can be statistically proven only in case of Spring soil sampling.


2019 ◽  
pp. 2-8
Author(s):  
L.V. Karpova ◽  
A.V. Strogonova

Наличие микроэлементов в почвах нашей страны находится в большом дефиците, что не позволяет оправдать биологический потенциал продуктивных показателей основных сельскохозяйственных культур. Цель исследований научное обоснование выбора наиболее эффективного способа применения комплексных жидких удобрений с микроэлементами в хелатной форме для формирования плотности агроценоза, посевных качеств и биохимического состава семян яровой пшеницы. Установлено, что в среднем за два года исследований полевая всхожесть яровой пшеницы на фоне естественного плодородия находилась в пределах 73,8-78,4, а на фоне внесения азофоски она составила 73,6-79,3. Наибольшее количество сохранившихся растений к уборке отмечено как на фоне без внесения удобрений, так и на фоне минерального питания в вариантах с обработкой семян Мегамикс-семена и Мегамикс-Профи в фазы кущения и колошения 386 и 388 растений на 1 м2. Микроэлементные удобрения оказали влияние на массу 1000 семян, энергию прорастания, лабораторную всхожесть и силу роста. При выращивании данной культуры на фоне внесения N16P16K16 масса 1000 семян увеличилась на 10,1 по вариантам опыта, энергия прорастания 9,4, лабораторная всхожесть на 6,9, масса 100 ростков на 17, а длина ростка 18,9. Биохимический состав зерна показывает запас питательных элементов: белка, азота, фосфора и калия, наибольшее количество которых накопилось в зерне яровой пшеницы, выращенной при обработке семян и посевов удобрениями Мегамикс-семена и Мегамикс-Профи .There is a great shortage of trace elements in the soils of our country, which does not justify the biological potential of the productive indicators of the main crops. The research objective is the scientific substantiation of the choice of the most effective way of applying complex liquid fertilizers with microelements in chelated form to form the density of agrocenosis, seedlings qualities and biochemical composition of spring wheat seeds. It was established that, on average, over two years of research, the field germination of spring wheat against the background of natural fertility was in the range of 73.8-78.4, and against the background of the application of nitrogen-phosphorus-potassium fertilizer it amounted to 73.6-79.3. The largest number of plants remained for harvesting was noted both against the background without fertilizer application and against the background of mineral nutrition in the variants with seed treatment with Megamix-seeds and Megamix-Profi in the tillering and heading stages - 386 and 388 plants per 1 m2. Micronutrient fertilizers influenced the weight of 1000 seeds, germination energy, laboratory germination and growth power. When growing this crop against the background of N16P16K16 application, the weight of 1000 seeds increased by 10.1 according to the experimental variants, germination energy - 9.4, laboratory germination by 6.9, weight of 100 sprouts - by 17, and sprout length - 18.9. The biochemical composition of the grain shows a supply of the following nutrients: protein, nitrogen, phosphorus and potassium, the largest amount of which was accumulated in spring wheat grain grown during the treatment of seeds and crops with fertilizers Megamix-seeds and Megamix-Profi.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1006A-1006 ◽  
Author(s):  
Paolo Sambo ◽  
Giorgio Gianquinto ◽  
Valente Forte

Several experiments on multispectral radiometer showed its suitability in driving nitrogen fertigation in tomato crop. Nir-Green light ratio describes crop nitrogen status well, highlighting element deficiency or excess, which is a great help to farmers in choosing timing and intensity of fertilizer application. The scientific literature reports several studies about nitrogen management only, but not phosphorus and potassium. Because of the advantage obtained with N, it would be desirable to also adapt it to phosphorus and potassium management. For this purpose, a preliminary trial was carried out on the omato cultivar Brigade grown in pots in a greenhouse. Four nutrient solution were supplied. Three were lacking in N, P, or K—the last had all elements needed for a balanced growth. Radiometer readings were taken once a week during the crop cycle, around noon. First results were encouraging. After some data elaboration, it appeared evident that, in some cases, it was possible to set the fertigation treatments apart by only having a look at the single wavelengths measured by the instrument. Through the Nir/green index, used in N management, phosphorus deficiency was identified as well. Potassium trend line was completely different from those of nitrogen and phosphorus, and very similar to that of the control. The utilization of the radiometer in handling potassium fertigation in tomato appeared somewhat difficult. Its application might be desirable, instead, for phosphorus fertigation in addition to nitrogen. The 560 and 710 nm wavelengths might be the especially more useful for this purpose, although a simple index or a combination of some simple indices able to identify phosphorous deficiency/excess and to screen them from those induced by nitrogen are needed.


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