Effects of nitrogen doses on growth and some nutrient element uptake of sunflower (Helianthus Annuus L.) hybrids

G. Ören1*, H. Çelik2

1Department of Soil Science and Plant Nutrition, Institute of Natural Sciences, Bursa Uludag University, Bursa, Turkey 2Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Bursa Uludag University, Bursa, Turkey

(Manuscript received 14 August 2018; accepted for publication 10 October 2018)

Abstract. Sunflower (Helianthus annuus L.) is known as one of the most important and preferred vegetable oil producing plants. In recent years, new cultivars with high oleic acid contents have been developed because of their health effects, extended frying and shelf life. On the other hand, nutrition of the plants is important for healthy growth, high yield, and oil quality and their nutrient needs may differ between the plant species and varieties. We aimed to determine the effects of increasing application doses of nitrogen (N) (0, 16, 32, 48, and 64 mg.kg-1 N) on growth and on some nutrient element uptake of four sunflower hybrids and compare the nutritional differences of linoleic (ESNovamis CL, and LG 5542 CL) and high-oleic (Oliva CL and ESGrafic CL) type sunflower hybrids in a greenhouse. The experiment was conducted in randomized factorial design with three replicates. Increasing doses of N effected the dry matter and nutrient uptake of sunflower hybrids significantly (p<0.01). Increasing doses of N elevated the dry weight, N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and boron (B) uptake of all tested sunflower hybrids. The increases were found maximum at 32 mg.kg-1 N dose. Significant differences were also established between the hybrids. Among the tested hybrids, ESGrafic CL a high oleic type sunflower has higher nutrient uptake capacity so much more nutrients might be supplied to this new generation sunflower hybrids according to the soil and plant analysis results.

Nitrogen uptake and expense in durum wheat depending on genotype and nitrogen fertilization

G. Panayotova1*, M. Almaliev2, S. Kostadinova2

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 2Department of Agrochemistry and Soil, Faculty of Agronomy, Agricultural University, 4000 Plovdiv, Bulgaria

(Manuscript received 29 September 2016; accepted for publication 30 January 2017)

Abstract. Nitrogen uptake and expense of durum wheat were studied under the conditions of fertilized field experiment on soil type Pellic vertisol. The seven genotypes – Progress, Vazhod, Victoria, Predel, Deana, Zvezdica and Elbrus selected at the Institute of Field Crops – Chirpan, Bulgaria, were grown in two field crops rotation of cotton and durum wheat under rainfed conditions for a period of three vegetations in years 2011-2013. The spring treatments of nitrogen as NH4NO3 were as follows: N0, N60, N120 and N180. The total N uptake in the above ground biomass of durum wheat increased with the amount of applied nitrogen and during climatically favorable years reached 220 kg N.ha-1. A tendency was found that the new genotypes uptook more N, compared to varieties Progress and Vazhod. The N expense of the new cultivars Predel and Zvezdica showed the highest amount of N per 1 ton of grain, 40.7 and 41.1 kg, respectively. Strong positive correlation was found between N fertilization and N uptake and expense for 1 ton of grain. The regression model indicated that N uptake with the grain and straw and N expense depending on N fertilization occurred with delay. With N fertilization of durum wheat at rates of up to 180 kg N.ha-1 each kilogram of applied N fertilizer increased the average expected N uptake with 7 kg.ha-1 and N expense with 0.66 kg.ton-1 grain.

Partial factor productivity of nitrogen fertilizer on grain and grain protein yield of durum wheat cultivars

G. Panayotova1*, S. Kostadinova2

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Agrochemistry and Soil Science, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria

(Manuscript received 19 January 2016; accepted for publication 2 February 2016)

Abstract. This study was conducted at the Field Crops Institute in Chirpan, Bulgaria, on Pellic vertisols soil type under non-irrigated conditions in the period of 2011 –2013. Tests were made on the effect of nitrogen fertilization at rates of 0; 60; 120 and 180 kgN/ha on seven durum wheat cultivars. The cultivar response was studied regarding the yield produced out of a unit of applied nutrient. It was found that the partial nitrogen productivity of grain and protein decreased by increasing the applied amounts of nitrogen fertilizer into the soil. The rate of N60 yielded the highest average partial productivity of nitrogen (69.8 kg/kg). The Elbrus and Deana cultivars had the highest partial nitrogen productivity of grain (47 –50 kg N/kg). The Elbrus cultivar manifested a tendency for the highest efficiency in forming the grain protein yield (7.2 kg N/kg) out of a unit of applied nitrogen fertilizer. The partial nitrogen productivity increased in favourable temperature and moisture weather conditions during wheat vegetation.


Nitrogen mineralization potential of alluvial meadow soil after long-term fertilization

V. Valcheva*, K. Trendafilov, M. Almaliev

Department of Agro-chemistry and Soil Science, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria

Abstract. The aim of this study was to investigate the nitrogen mineralization potential of alluvial meadow soil after continuous fertilization. Our research was focused on a long-term field experiment with different variants of fertilization set in 1959 in the Experimental field of Agricultural University-Plovdiv. Since 2006 the fertilization has been discontinued. In 2010 and 2011, we collected soil samples from depth 0 – 30cm and from the following variants: 1 – control, 2 – N50P30K20, 3 – N25P15K0 + 6 t/da manure, 4 – N50P0K20. In accordance with relatively high content of total nitrogen, the nitrogen mineralization potential of the soil is high. The maximum amount of nitrogen, susceptible to mineralization at optimum temperature and humidity ranges from 233.21 to 350.90 mg N/kg soil. The proportion of potentially mineralizable nitrogen from the total nitrogen in soil is low – average 17%. The reason for this is the humic type of soil organic matter. Also in its composition dominated black humic acids, which are bonded with Ca and resistant to decomposition. Sufficient amount of clay particles and micropores provide physical protection of organic matter from microbial activity. The mean value of mineralization rate constant (k), 0.041, denotes that at optimal conditions the mineralizable N fraction is released at an average rate of 4,1% per week, based on the quantity of mineralizable N remaining after each succeeding week of incubation.


Bioconversion of nitrogen in an eco-technical system for egg production

A. Gencheva*

Nature Sciences Department, New Bulgarian University, 21 Montevideo, 1618 Sofia, Bulgaria

Abstract. The present paper aims to assess nitrogen circulation in an eco-technical system for egg production. The experiments were conducted in modelled conditions in an anthropogenic ecosystem of the “mesocosm” type, in which the unit of the bio-consumers and three eco-technological chains modelling the unit of the bio-decomposers are modelled: manure storing for decontamination /a recommendation on good farming practices/, composting and anaerobic decomposition in an installation for biogas production. A new criterion was implemented for the assessment of the chemical heterogeneity in the biogenic nitrogen cycle in the modified trophic chain – retention coefficient /k/, which is defined as the ratio of nitrogen introduced into the system / nitrogen content in the feed: its quantity in the secondary biological production x 100. The chemical heterogeneity at the level of organisms /differences in the individual components of eggs/ and at the biocenotic level is established. The biogenic nitrogen cycle in the eco-technical chain for egg production is characterized by an uneven distribution in both products of the outflow. The largest amount of nitrogen is found in the egg whites (k = 0.45), while it decreases significantly in egg yolks (k = 0.17) and reaches k = 0.03 in the egg shell, a.k.a. heterogeneity on the level of organisms is established. The nitrogen compounds introduced through the feed ration are concentrated in manure (k = 25.33). Losses of nitrogen are established in two of the manure utilization technologies. The quantity of /k/ in the compost is 20.32, a.k.a. the loss of nitrogen compounds is 19.8%. The biggest losses are found in manure storage; according to the recommendations on good farming practices (k = 18.82) or the reduction of nitrogen is 25.7% compared with fresh manure. Due to redistribution of the chemical elements /a significant part of C, H and O are included in biogas/, there is nitrogen concentration in bio slime – k = 35.85 or 41.5% more than in fresh manure. When separated nitrogen is concentrated in the liquid fraction (k = 31.19), while in the solid phase k = 4.67 is established.


Influence of universal liquid fertilizer MaxGrow on yield and quality of durum wheat (Triticum durum Desf.) cultivar Progress

G. Panayotova, A. Stoyanova
Abstract. During the period 2008 – 2010 the response of durum wheat cultivar Progress, grown on Eutric Vertisols at the field of the Field Crops Institute, Chirpan, Bulgaria to foliar feeding with universal liquid fertilizer MaxGrow was studied. The fertilizer was applied once and twice during tillering – beginning of stem elongation stage at doses of 3 and 5 l/ha, alone and in combination with N120 fertilization. The results showed that foliar feeding with MaxGrow improved growth, yield and grain quality and was an effective agronomic activity for durum wheat. Under single foliar feeding with 3 and 5 l/ha the average grain yield increased by 3.6 to 10.2 % over the check, whereas at twofold spraying with the same doses yields increased by more than 9.9 and 15.5 %. The liquid fertilizer MaxGrow can be successfully used at a dose of 5 l/ha for durum wheat feeding. After combined foliar and N fertilization the grain yield exceeded the standard N120 fertilization by 0.12–0.22 t.ha-1 and for the same period it reached 4.27 t.ha-1. MaxGrow had a favorable effect on the grain quality. Under the influence of MaxGrow and nitrogen fertilization, the plant height at the end of vegetation exceeded by 24.6–26.2 % compared to the water check, the test weight ranged from 79.98 to 80.73 kg.hl-1, the 1000 kernel weight increased by 5.6–7.0 %, vitreousness – by 40.7 to 48.8 %, the crude protein content – to 24.8 % and wet gluten – to 14.9 % over the water control.


Influence of liming with Ca(OH)2 on nitrogen, phosphorus and potassium content in foliage of vine varieties

K. Trendafilov, V. Valcheva, S. Todorova
Abstract. In conditions of combined field experiment the influence of liming with Ca(OH) was studied in rates of 1,0, 2,5 and 5,0 t/ha on the input of nitrogen, 2 phosphorus and potassium in the leaves of fertility vines from varieties Sauvignon Blanc, Chardonnay, Cabernet Sauvignon and Merlot, planted on Chromic luvisol. Samples were collected in three consecutive years; the first sampling time is 15 months after the incorporation of lime into the soil and the second and third – at intervals of 12 months. Nitrogen content in foliage established in all measurements from first sampling of leaves showed no significant differences between the variants. In subsequent years higher nitrogen content was found in the leaves of all varieties and the excess, compared to the first year is best expressed in the red varieties, mainly in Merlot variety. There are significant differences between varieties in relation to phosphorus content in air-dried leaves. There is a trend to increase the absorption of phosphorus when applying meliorative lime rates of 1,0 and 2,5 t/ha, while the rate of 5,0 t/ha inhibits the accumulation of phosphorus in leaves.As regards the absorption of potassium similar patterns were found as for phosphorus. No significant difference between the content of potassium in the three consecutive years of sampling was found. Differences in absorption of potassium between the red and white wine varieties are more clearly pronounced than the differences between varieties in relation to content of phosphorus and nitrogen.


Chemical composition of sediments from fish ponds as a natural biological product

D. Terziyski, L. Hadjinikolova

Abstract. The aim of this study is related with the characterization of the chemical parameters of sediments obtained from intensive carp ponds, as a natural biological product. Vertical differentiation in the levels of the studied chemical indicators of sediments was established. At 0–15 cm horizon the active reaction values were between 2% and 6% higher, the content of organic nitrogen was on average 47.95% higher, and that of ammonium and nitrate ions on average 34% – 37.85% higher, comparing with the recorded for 15 –30 cm horizon. At 15–30 cm horizon the organic matter content was on average 30.4% higher, that of phosphate ions with 13.1% higher, comparing to this of 0 –15 cm horizon.