Levels Of Phosphorus Fertilization Research Articles

Straw Mulching Combined with Phosphorus Fertilizer Increases Fertile Florets of Wheat by Enhancing Leaf Photosynthesis and Assimilate Utilization

Lack of soil moisture and phosphorus deficiency limits wheat grain yield in dryland areas. However, the moisture-conserving effect of straw mulching combined with phosphor fertilization on fertile florets per spike (FFS) and grain yield remains unclear. During the 2020–2021 and 2021–2022 growing seasons, we investigated the combined effects of straw mulching (0 and 8000 kg ha−1) and phosphorus fertilization (0, 75, and 120 kg P2O5 ha−1) on spike development, assimilates’ availability, and the photosynthetic properties of flag leaves by conducting a field experiment. Compared with no straw mulch control, straw mulching increased fertile spike, grain number per spike (15.6%), and grain yield (22.6%), and grain number per spike was the most important contribution to increasing wheat grain yield (46%). An increase in grain number per spike is associated with FFS. Compared with no straw mulch control, straw mulching increased FFS by 19.5%, and it increased with increasing phosphorus fertilization levels. Moreover, straw mulching combined with phosphorus fertilization promoted the light compensation point (LCP), light saturation point (LSP), net photosynthetic rate (Pn), Chl b, and the maximal photochemical efficiency of photosystem II (Fv/Fm) of flag leaves to produce carbohydrates. Our study has shown that the primary factor for the divergence in FFS under straw mulching and phosphorus application was the efficiency of assimilate utilization in the spike, which ultimately led to increased grain number per spike and grain yield.

Effect of Elevated CO2 and Temperature on Phosphorus Harvest Index of Wheat (Triticum aestivum L.) at Various Levels of Phosphorus Fertilization

The possible alteration in plant growth, productivity and phosphorus (P) demand of wheat under rising atmospheric CO2 and temperature is expected to influence the partitioning of P to different plant parts of wheat. A phytotron experiment was conducted to study the effects of elevated atmospheric CO2 (650 µmol mol-1) and elevated temperature (ambient + 3 °C) on phosphorus harvest index of wheat at various levels (control, 100% and 200% of recommended P) of P fertilization. While there was a slight increase (5.6%) in P harvest index of wheat under elevated CO2, the reverse trend (12.7% decline) was observed under elevated temperature with no consistent effect at various levels of P fertilization. Interestingly, there was a moderate decline (7.7%) in P harvest index of wheat under combined elevation of CO2 and temperature as compared to their ambient combination. The results suggest that temperature could be the dominant factor as compared to the atmospheric CO2 in deciding the overall impact of projected increase in atmospheric CO2 and temperature on P harvest index of wheat. As there is logically possible relationship between P harvest index of wheat and various physical and nutritional qualities of wheat grains such as grain Zn and Fe content and their bio-availability, grain protein content, seedling vigour, etc., the decline in wheat’s P harvest index under projected levels of CO2 and temperature in our study underscores the need of undertaking elaborate experimentations to investigate the probable effects of climate change on quality parameters associated with P harvest index of wheat.

Rye Production under Acid Soils and Drought Conditions: An Alternative for the Sustainability of High Andean Livestock Farming in Peru

The rye (Secale cereale L.) crop shows a high potential to contribute to the sustainability of high Andean livestock because it supports the agroclimatic conditions and acid soils in the Peruvian Andes. The production of green forage, hay, and grain from the rye crop in acid soils was studied with the use of different levels of phosphorus and potassium fertilization in four local rye ecotypes (CBI-001, CSM-001, CJS-001, and CCE-001). The green forage yield (GFY) ranged from 32.35 to 53.62 t ha−1, dry matter from 6.05 to 8.56 t ha−1, and hay from 7.0 to 10.36 t ha−1; nutritional levels ranged from 9.02% to 13.56% protein and 6.50% to 7.75% ash levels, mainly with differences between ecotypes (p < 0.05). No differences existed between fertilization levels for the number of stems per plant, spikes per plant, and grains per ear (p > 0.05). Also, CBI-001 and CCE-001 were superior with 1868.4 and 1797.8 kg ha−1 of grain, respectively (p = 0.0072); the use of 60 kg ha of nitrogen, 120 kg ha−1 of P2O5, and 80 kg ha−1 of K2O gave higher grain and residue yields. The high nutritional value and yield of the rye ecotypes studied in acid soil conditions and without irrigation can be an alternative for livestock feeding and grain production in the rainy season in the Andes as a dual-purpose crop.

Sustainable production ofSaussurea costus under different levels of nitrogen, phosphorus and potassium fertilizers in cold desert region of Western Himalaya.

Saussurea costus, an important critically endangered medicinal herb native to the Himalayan region, is commonly used in various ailments, viz. asthma, ulcer, inflammation, and stomach problems. In the international market, the dry roots and essential oil of S. costus has become an important drug. The lack of appropriate fertilizer dose recommendations is one of the limiting factors for its ex-situ conservation and large-scale cultivation, as plant nutrition is vital in determining crop growth and productivity. The study aimed to understand the comparative impact of different levels of fertilizer nutrients on growth, dry root and essential oil yield, and essential oil profile of S. costus. A field experiment was conducted in Himachal Pradesh, India's cold desert region (Lahaul valley), during 2020-21. The experiment comprised three levels of nitrogen (60, 90, and 120 kg ha-1), three levels of phosphorus (20, 40, 60 kg ha-1), and two levels of potassium (20 and 40 kg ha-1) in a factorial randomized block design. The fertilizer application had an immense effect on growth attributes, root yield attributes, dry root yield, and essential oil yield over control. The treatment combination N120, P60, and K40 had the largest effect on the plant height, number of leaves per plant, leaf length and width, root length and diameter, dry matter per plant, dry root yield, and essential oil yield. However, the results were at par with the treatment comprising N90, P40, and K20. Dry root yield increased by 108.9%, and essential oil yield increased by 210.3% with fertilizer applications over unfertilized plots. The regression curve shows an increasing trend in dry root yield till N90, P40, and K20; after that, it nearly stabilized. The heat map showed that applying fertilizer significantly affected the chemical constituents of S. costus essential oil. Similarly, the plots fertilized with the highest level of NPK recorded the utmost value of available N, P, and K, as compared to unfertilized plots. The results emphasize that for sustainable cultivation of S. costus, the application of N90, P40, and K20 combinations is the most suitable one.

Quantitative and Qualitative Yield of Groundnut (Arachis Hypogaea L.) in Response to Intercropping Pattern and Integrated Application of Chemical and Biological Phosphorus Fertilizers

ABSTRACT Intercropping between cereals and legumes can increase resource use efficiency, agricultural productivity, and yield sustainability and reduce chemical inputs. For these reasons, this experiment was performed as factorial arrangement based on randomized complete block design with three replications in experimental station of Guilan Agricultural and Natural Resources Research and Education Center, Rasht, Iran in 2016 and 2017 cropping seasons. Experimental treatments included five levels of phosphorus fertilizer (PF) as triple super phosphate (TSP) including : 1- Zero (as control), 2–50 kg ha-1 TSP, 3–100 kg ha-1 TSP, 4–50 kg ha-1 TSP+200 g ha-1 Barvar2 phosphate bio-fertilizer (BPB) and 5–100 kg ha-1 TSP+200 g ha-1 BPB, and five IPs (IP) including: 1- maize (Zea mays L.) sole cropping, 2- groundnut sole cropping, 3- intercropped groundnut-maize with the ratio of 1:1, 2:1 and 1:2 rows, . Although, maximum grain yield of maize and groundnut was obtained in response to the application of 100 kg ha-1 TSP plus 200 g ha-1 BPB under sole cropping, the highest land equivalent ratio (LER) was observed under zero usage of TSP and intercropped maize-groundnut with the ratio of 1:1 rows. Crops in intercropping system have a complementary effect together. In this experiment, LER values greater than 1.00 indicated an intercrop advantage to sole crop. Results showed that IP increases the quantity and quality of products by increment in plant diversity, ecological balance, more utilization of resources, and reduction of damage by pests, diseases, and weeds in agricultural ecosystems.

Response of Sweet Sudan Grass to Graded Levels of Phosphorus and Potassium Fertilization

Background: Green fodder yield potential of the landmark multi-cut sweet sudan grass (SSG) variety SSG 59-3 was influenced due to the poor fertility status at many places in Haryana. The performance of sweet sudan grass under different P and K treatments was assessed by measuring fodder yield, agronomic efficiency, physiological efficiency and net income. Methods: A two-year (2018 and 2019) field study was conducted at Hisar, Haryana to assess the effect of four P levels (0, 6.6, 13.2 and 19.8 kg/ha P) and four K levels (0, 12.5, 25.0 and 37.5 kg/ha K) on growth, yield and quality of sweet sudan grass (SSG-59-3). The sixteen treatment combinations were replicated thrice in a factorial RBD. The sandy-loam soils of the experimental field was low in organic carbon (0.47%) and available nitrogen (141 kg/ha) and medium in available P (12.9 kg/ha) and K (225 kg/ha). The nutrients P and K were applied through di-ammonium phosphate and muriate of potash just before sowing. Result: The graded levels of P and K gave significantly better results up to 13.2 kg/ha P and 37.5 kg/ha K. The agronomic efficiency, physiological effecicency and apparent nutrient recovery (%) of nutrients were highest with lower levels of P and K (6.6 and 12.5 kg). The application of K had complementary effect on the uptake of P as appropriate ratios of N, P and K fertilizer improved absorption and utilization of nutrients.Therefore, farmers can apply 13.2 kg P/ha plus 37.5 kg K/ha along with recommend N for increased dry fodder yield and net income in sweet sudan grass.

Effect of spraying with potassium silicate and phosphorus fertilizer levels on growth, yield and fruit quality of eggplant plants under low temperatures stress.

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Role of Arbuscular Mycorrhizal Fungi and Phosphate Solubilizing Bacteria in Improving Yield, Yield Components, and Nutrients Uptake of Barley under Salinity Soil

Barley (Hordeum vulgare, L.) is the fourth most important cereal crop in the world. Salinity decreases the productivity of plants grown under salinity conditions. It leads to deficiency and limited absorption of water and nutrients, ionic stress, oxidative stress, and osmotic imbalance. In saline soil, a field experiment was conducted to verify the effects of nine combinations among three levels of bio-fertilizers, i.e., control (without), arbuscular mycorrhizal fungi (AMF), and phosphate solubilizing bacteria (PSB), as well as three levels of phosphorus fertilizer recommended dose (RDP) on barley yield, its components and nutrients uptake, to evaluate the useful influences of these combinations to improve P management under salinity stress related to yield and its components as well as N, P, and K uptake in barley. Findings revealed that the combination AMF + 100% RDP improved plant height, length of spike, spikes weight, number of spikes plant−1, weight of 1000-grain, straw yield, grain yield, uptake of nitrogen (N), phosphorus (P), potassium (K) in grain and uptake of nitrogen (N), phosphorus (P), potassium (K) in straw by 19.76, 33.21, 40.08, 33.76, 14.82, 24.95, 47.52, 104.54, 213.47, 168.24, 124.30, 183.59, and 160.84% in the first season, respectively. Meanwhile, the increase was 19.86, 29.73, 40.47, 39.94, 14.92, 24.95, 47.94, 104.73, 213.33, 168.64, 124.47, 183.86, and 161.09% in the second season, respectively. AMF showed greater efficiency and effectiveness compared to PSB in improving yield and its components for all studied traits. The results of principle component analysis indicated that all combinations except AMF + zero% RDP, PSB + zero% RDP, control + zero% RDP, and control + 66% RDP showed high scores on positive PC1, where all studied traits were high. Therefore, it is recommended to inoculate the soil with AMF or PSB with the addition of phosphate fertilizer at the recommended dose under salinity conditions, i.e., AMF + 100% RDP (T1) or AMF + 66% RDP (T2) or PSB + 100% RDP (T4). The use of bio-fertilizers has increased plant tolerance to salt stress, and this was evident from the increase in different traits with the use of treatments that include bio-fertilizers.

Impact of nitrogen and phosphorus fertilizers on Cry1Ac protein contents in transgenic cotton.

Application of different fertilizers to check the efficiency of expression of Bt (Bacillus thuringiensis) gene in one of the leading commercialized crops (cotton) against Lepidopteran species is of great concern. The expression of Cry protein level can be controlled by the improvement of nutrients levels. Therefore, the myth of response of Cry toxin to different combinations of NP fertilizers was explored in three Bt cotton cultivars. Combinations include three levels of nitrogen and three levels of phosphorus fertilizers. Immunostrips and Cry gene(s) specific primer based PCR (Polymerase Chain Reaction) analysis were used for the presence of Bt gene that unveiled the presence of Cry1Ac gene only. Further, the ELISA (enzyme-linked immunosorbent assay) kit was used to quantify the expression of Cry1Ac protein. Under various NP fertilizers rates, the level of toxin protein exhibited highly significant differences. The highest toxin level mean was found to be 2.3740 and 2.1732 µg/g under the treatment of N150P75 kg ha-1 combination while the lowest toxin level mean was found to be 0.9158 and 0.7641 µg/g at the N50P25 kg ha-1 level at 80 and 120 DAS (Days After Sowing), respectively. It was concluded from the research that the usage of NP fertilizers has a positive relation with the expression of Cry1Ac toxin in Bt cotton. We recommend using the N150P50 kg ha-1 level as the most economical and practicable fertilizer instead of the standard dose N100P50 kg ha-1 to get the desired level of Cry1Ac level for long lasting plant resistance (<1.5). The revised dose of fertilizer may help farmers to avoid the cross-resistance development in contradiction of insect pests.

USING PHOSPHATE SOLUBILIZING BACTERIA TO ENHANCE PRODUCTIVITY OF TWO LENTIL VARIETIES

Two field experiments were conductedunder surface irrigation system during two successive winter growing seasons 2017/2018 and 2018/2019in private farm atEl Qantra-West, Ismailia Governorate,Egyptto evaluate the effect of the combinations of three levels of phosphorus fertilizer (0, 15.5 and 31.0 kg P

Evaluation of the performance of some cultivars of Faba Bean Vicia faba L. under different levels of phosphorus

A field experiment was carried out during winter season of 2021-2022 to study growth and yield performance of four faba bean cultivars (lo-cal, Spanish, Dutch and New Zealand) and evaluate their performance under three levels of phosphorus fertilizer (80, 120 and 160 kg ha-1). The experiment was applied in split plot design with three replications. results showed highly significant effects of fertilization on all measured traits, as the third level (160 kg ha-1) superior in all measured traits, and gave plant dry weight (171.33 g) and seed yield (4.403 Mg ha-1). local cultivar was superior in traits: plant height, total phosphorus content, phosphorus use efficiency and plant dry weight. As for New Zealand cultivar excelled in: number of branches, number of leaves, and phosphorus concentration in shoot. while Spanish cultivar was superior in total seed yield (5.295 Mg ha-1).

Response of tuberose to different levels of nitrogen, phosphorus and potassium fertilizers

Response of tuberose to different levels of nitrogen, phosphorus and potassium fertilizers

Effect of Sowing Date and Phosphorus on Growth, Seed Yield and Quality of Fenugreek

The effect of sowing date (three sowing dates viz., S1= 01 November, S2= 15 November and S3= 30 November) and phosphorus levels (four phosphorus fertilizer levels viz., P0= Control, P1= 35 kg P ha-1, P2= 45 kg P ha-1 and P3= 55 kg P ha-1) on growth, seed yield and quality of fenugreek was investigated at Horticulture Farm, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, during 10 October 2020 to April 2021. Growth-related data was maximum on S1 (01 November) treatment but S2 (15 November) treatment showed the best result in case of seed yield. In case of growth characters, P3 (55 kg ha-1) revealed the best result but in case of seed yield, P2 (45 kg ha-1) treatment showed the best effect. Under this investigation, it was revealed that the maximum growth was obtained by S1P3 (01 November with 55 kg P ha-1) and the minimum growth was obtained by S3P0 (30 November with control) treatment combination. The maximum pods per plant (52.61), seeds per pod (12.87), weight of individual pod (147.11 mg), the weight of seeds per plant (7.67 g) and weight of 1000-seed (13.86 g), seed yield per plot (306.72 g), seed yield per hectare (2.13 t) and vigor index (570.27) was observed from the treatment combination S2P2 (15 November with 45 kg P ha-1). It was concluded that the combination of sowing date S2 (15 November) along with phosphorus application P2 (45 kg P ha-1) were given the better performance of all the yield contributing parameters and seed yield of fenugreek. So, S2P2 (15 November with 45 kg P ha-1) treatment combination can be repeated in different agro-ecological zones of Bangladesh.

UMA MISTURA DE FUNGOS MICORRÍZICOS ARBUSCULARES FAVORECE MUDAS DE AROEIRA-VERMELHA EM NÍVEL INTERMEDIÁRIO DE FÓSFORO DO SOLO

ABSTRACT Several tropical woody species are highly responsive to arbuscular mycorrhizal fungi (AMF) and depend on their symbiosis for nutrition and successful establishment in the field. The objective of this study was to evaluate the response of Schinus terebinthifolius, a native species of the Brazilian Atlantic Forest and Caatinga, to inoculation with three AMF species (Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus), either individually or mixed, at different levels of phosphorus fertilization (0, 71, 213, and 650 mg kg−1 of P). We conducted the experiment in 1 kg pots, following a completely randomized design with six replicates per treatment, to evaluate morphological and nutritional traits after 116 days, including stem diameter, plant height, plant biomass, and shoot P content. Our results showed that S. terebinthifolius was highly dependent on mycorrhizae and presented different responses depending on the AMF species. The greatest total biomass accumulation occurred when a mixture of the three AMF species was used, which indicated synergism between the fungi. The highest overall positive response to inoculation were observed at an intermediate P level (213 mg kg−1), and although shoot biomass was reduced at the intermediate P doses, an increase in root biomass compensated for this. These results indicate complementarity as opposed to functional redundancy of the AMF species and highlight the importance of using a mixed inoculum in seedling production of S. terebinthifolius for revegetation programs.

Physical and physicochemical characteristics of tomato fruits grown under different irrigation water levels and phosphorus sources and rates

Phosphorus (P) is one of the most limiting nutrients for growth and development of crops, and is important for soil fertility managements, since it affects the quality of fruits. With the hypothesis that different levels of irrigation and phosphorus fertilization interfere in the physical and physicochemical properties of tomatoes, the objective of this experiment was to verify this hypothesis and analyze the behavior of the fruits’ responses. The experiment was conducted in a greenhouse at the Hydraulic and Irrigation Laboratory of the Federal Institute of Education, Science, and Technology of the State of Goiás, in Rio Verde, Goiás, Brazil. A randomized block design was used, with a 4×2×4 split-plot arrangement and three replications, totaling 96 experimental plots. The treatments consisted of four P2O5 rates: 25%, 50%, 100%, and 200% of the recommended rate; two P sources: monoammonium phosphate (MAP) and organo-mineral (OM); and four IWL: 50%, 75%, 100%, and 125% of the field capacity. The fruits were evaluated for longitudinal (FLD) and transversal (FTD) diameters, potential hydrogen (pH), titratable acidity (TA), total soluble solid (TSS) contents, and TSS to TA ratio (TSS/TA). The effect of the interactions between the factors IWL and P rate, IWL and P source, and P rate and source were significant for FLD and FTD, TSS, TA, and TSS/TA. The effects of the interactions between IWL and P rate, and IWL and P source were significant for pH. The MAP source combined with the rate of 25% and IWL of 125% resulted in tomato fruits with larger FLD and FTD. The rate of 25% combined with IWL of 77% and 100% resulted in tomato fruits with higher TSS and pH. The OM source resulted in tomato fruits with higher TA when combined with IWL of 50%, and larger FLD when combined with IWL of 105% and 125%.&#x0D; (This article belongs to the Special Issue: Agricultural Water Management in Arid and Semi-arid Regions)

Dynamics of Phosphorus and Biostimulants on Agro-Morphology, Yield, and Essential Oil Profile of German Chamomile (Matricaria chamomilla L.) Under Acidic Soil Conditions of the Western Himalaya.

German chamomile (Matricaria chamomilla L.) is a promising and easy to cultivate crop under suitable nutrient supply conditions, but acidic soils of Indian western Himalayas limit the availability of phosphorus to the plant and reduce flower production. Thus, a field experiment was conducted for two consecutive seasons (2018–2019 and 2019–2020) to study the effect of phosphorus dynamics and biostimulant application on the agro-morphological traits, essential oil (EO) yield, and chemical constituents of German chamomile in the mid hills of the western Himalayan region. The experiment consisted of 12 treatments, four phosphorus fertilizer levels (0, 30, 60 and 90 kg ha−1) and three biostimulants levels (control, amino acid at 5 mL L−1, and humic acid at 10 mL L−1). The experiment was replicated three times in a factorial complete randomized block design (FRBD). Agro-morphological and yield characteristics were significantly higher in phosphorus at 90 kg ha−1 and humic acid application compared to the control. Dry flower and EO yield was 17.87 and 26.76% higher with the 90 kg ha−1 phosphorus application while 2.45 and 5.79% higher in humic acid at 10 mL L−1 compared to the control. The EO constituents viz., chamazulene was 12.04 and 8.85% higher in phosphorus at 90 kg ha−1 and humic acid at 10 mL L−1 application compared to the control. On the other hand, α-bisabolol oxide B and α-bisabolol oxide A were decreased with increase in phosphorus application. This study presents novel facts, elucidation, and explanation for farmers and industrialists to produce German chamomile in acidic soils by integrating biostimulants with phosphorus fertilization and getting maximum yield and quality EO.

Effect of Nitrogen, Phosphorus and Potassium on Yield, Quality, Nutrient Content and Uptake on Hybrid Maize (Zea mays L.)

Background: Maize (Zea mays L.) is one of the most versatile emerging crops having wider adaptability under varied agro-climatic conditions. Nitrogen though an expensive input is very important as it is intimately involved in the process of photosynthesis and directly reflected in the total dry matter production. Phosphorus is involved in a wide range of plant processes from permitting cell division to the development of a good root system and for ensuring timely and uniform ripening of the crop. Potassium plays a vital role as macronutrient in plant growth and sustainable crop production. The current study aimed to study the effect of nitrogen, phosphorus and potassium on yield, quality, nutrient content and uptake on hybrid maize (Zea mays L.) under south Gujarat condition. Methods: A field experiment was conducted during rabi season of the year 2019-20 to study the effect of different levels of nitrogen, phosphorus and potassium on yield, quality, nutrient content and uptake by hybrid maize (Zea mays L.). In this experiment twelve treatment combinations consisting of three levels of nitrogen fertilizer, two levels of phosphorus fertilizer and two levels of potassium fertilizer were tried in factorial randomized block design with three replications. The protein content and nitrogen, phosphorus, potassium content and their uptake by seed and stover and available nitrogen, phosphorus, potassium status in the soil after harvest of the crop were determined by different methods. Result: The result showed that quality parameter viz., crude protein content, crude protein yield, nutrient content and uptake by grain and straw of hybrid maize were increased with the increased in nitrogen (180 kg N ha-1), phosphorus (60 kg P2O5 ha-1) and potassium (30 kg K2O ha-1) level.

Response of Some Growth Traits of Safflower(Carthamus tinctorius L.) to Spray with Humic Acid Under Levels of Phosphorus Fertilizer

The research was carried out in Agriculture College farm / Basra University – Karmat Ali location, the winter season 2020- 2021, to study the response of Safflower variety Gilla to spray with four concentrations of humic acid (0,6,12,18g L-1) under four levels of Phosphorus fertilizer(0,60,120 kg P h-1). The experiment was carried out in a factorial arrangement with three replications using a randomized complete block design. The results showed that 120 kg P h-1 gave of the highest days until 50% flowering, plant height, the total number of main branches and leaves and a diameter of the stem (106.75 days ago, 183.01cm,12.44 branches plant-1, 588.71 leaves plant-1,1.466cm respectively). The maximum number of days to 50% flowering plant height, the number of main branches were superior with a humic acid concentration of 12 g L-1., (109.56 day,180.34cm and 12.70 branches plant-1respectively), while concentration 18 g L-1 gave the highest number of leaves. The interaction of 120 kg P h-1 with 12 g L 1- of humic acid gave the highest number of days from planting to 50% flowering, plant height, the number of main branches.

Efficiency of Phosphorus Use in Sunflower

Sunflower is an oleaginous plant of great importance worldwide that stands out in the production of edible oil and human food. The identification of differences between cultivars regarding the use of phosphorus and the production of achenes at different levels of phosphate fertilization is a viable strategy to allow its cultivation in soils with different concentrations of phosphorus, without compromising yield and reducing environmental damage associated with excessive applications of phosphate fertilizers. Thus, the objective of this study was to evaluate different levels of phosphorus fertilization and sunflower cultivars regarding the efficiency of phosphorus use in two agricultural crops. The experimental design was in randomized blocks with four replications in split-plots, where four doses of phosphorus (50, 100, 150, and 200 kg ha−1 of P2O5) were allocated in the plots, and in the subplots three sunflower cultivars (Aguará 06, Altis 99, and BRS 122). The phosphorus use efficiency of sunflower cultivars was estimated through agronomic efficiency, vegetative efficiency, agrophysiological efficiency, apparent recovery efficiency, and utilization efficiency. The dose of 50 kg ha−1 of P2O5 provided the best phosphorus efficiency indices for the different sunflower cultivars in the two studied crops. Cultivar Aguará 06 was more efficient in conditions with P2O5 supply below 150 kg ha−1, regardless of the crop. Sunflower cultivars had the best efficiency indices of phosphorus applied in the 2016 harvest.

Response of Soybean (Glycine max L.) Varieties to Different Rates of Phosphorus Fertilizer on Yield and Yield Components at Omo Kuraz, Southern Ethiopia

Soybean (Glycine max (L.) Merrill) is the most important source of protein, oil and also cash for poor farmers. Lack of improved variety and optimum phosphorus fertilizer rate are the most important limiting factor for the productivity of soybean. Therefore, an experiment was carried out at Omo Kuraz-1 Sugar Development Project during 2018 cropping season to determine the effect of phosphorus (P) fertilizer levels on yield and yield related traits of soybean varieties. Factorial combination of three soybean varieties (Nova, Awassa-04 and Gazolia) and four rates of P fertilizer (0, 23, 46 and 69 kg P205/ha were laid out in a RCBD with three replications. Data were collected for yield and yield components and analyzed using Statistical analysis software (SAS and Genstat). The analyses of variance showed that there was significant difference (p≤ 0.001) among the varieties for the entire tested parameters, indicating the presence of ample genotypic variation among then Awassa-04 Variety produced significantly high grain yield (1183 Kg ha-1 as compared to Gazolia (950 Kg ha-1) and Nova (566 Kg ha-1). Interaction of variety Awassa-04 with 69 Kg P205 ha -1 showed maximum grain yield (1352 Kg ha-1) while the minimum value (403 Kg ha-1) was recorded for interaction of Nova variety with 0 kg P205 ha-1. Based on the economic analysis phosphorus fertilizer application at rate of 69 Kg P205 ha –1 resulted in highest marginal rate of return (350.9%). Therefore, it was conclude that phosphorus fertilizer application at rate of 69 Kg P205 ha-1 can be recommended for the study area. However, further study should be done on different rate of phosphorous to come up with a more comprehensive recommendation.