This study was conducted to determine the residual effects of chicken manure applications on nutrients in leaves and bulbs of second crop onion that grown after lettuce in greenhouse conditions. In the study, residual effects of chicken manure in 4 different doses (control, 20 t ha-1, 40 t ha-1, 60 t ha-1) and chemical fertilizers applied in the recommended amounts are investigated. Three onion varieties, called Burgaz, Snow white, Champion, were used. In the study, the lowest nutrient uptake was observed in control. However, the highest mineral content in leaves and bulbs were determined in the plots, that on average 40 t ha-1 chicken manure was applied to. In terms of leaf nutrient content, when the varieties were compared to each other, Ca, Mg, and Cu contents were found to be the highest in the Burgaz variety. Phosphorus, Zn, Mn contents were analyzed to be the highest in Snow white while N values determined maximum in Champion. The Champion variety contained higher nutrient values in bulbs.

Globally, rising coffee consumption has led to an increase in coffee grounds waste. This study evaluated the feasibility of using spent coffee grounds (SCG) as an alternative fertilizer in agriculture from an environmental perspective. To this end, various application rates of coffee grounds (0, 7.5, 15, and 30 t ha⁻¹) were tested to determine their effects on the yield and nutrient content of red radish, as well as on selected physical and chemical soil properties. Coffee grounds applications significantly increased the organic matter content and the amounts of N, P, K, Mg, and Zn in loamy sand soil following radish cultivation. Compared with the control, 30 t ha⁻¹ of SCG raised soil organic matter by 50% and enhanced P, Mg, and Mn contents by 27.5%, 14.6%, and 55.5%, respectively. SCG treatments significantly improved the P, Mg, Zn, and Mn contents in radish leaves and tubers, as well as K and vitamin C levels in the tubers. Notably, the 30 t ha⁻¹ dose increased tuber Mg and Mn contents by 32% and 55%, respectively, while the 15 t ha⁻¹ dose increased vitamin C content by 35%. However, these applications did not affect radish tuber yield, dry matter content, leaf N, Fe, and Cu levels, or tuber N, Ca, and Fe concentrations. Consequently, the application of spent coffee grounds enriched the mineral profile of radish, an important nutritional source, thereby enhancing its overall nutritional value. The findings indicate that spent coffee grounds applications to soil can improve the mineral content of both plants and soil while also enhancing soil properties, suggesting significant potential as an alternative fertilizer. Additionally, repurposing large quantities of coffee grounds in agriculture contributes to sustainable soil fertility and offers environmental benefits.

The study was carried out to the effects of different plant densities and nitrogen levels on okra yield and plant development. Field trials were conducted in two locations, the training fields of the Ege University, Ödemiş Research and Training area, and Ege University Faculty of Agriculture, Menemen Research and Training Farm. The field layout was a split-plot design with 3 replicates, where main plots consisted of nitrogen applications and sub-plots of plant densities. Fertilizer was applied in the form of Triple Superphosphate, Potassium Sulfate, Urea and Ammonium Nitrate. Five different nitrogen levels (F1: 0, F2: 40, F3: 80; F4: 120 and F5: 160 kg N ha-1) and two different rows spacing (PD1: 15 cm×70 cm and PD2: 25 cm×70 cm) have been tested. Yield and yield components, plant height at flowering, height of the first fruits, the number of leaves, the number of branches, the number of days from sowing to first flowering, the number of days from sowing to first harvest, plant height, foliation status, total yield, yield of plant, average fruit weight, fruit length, fruit diameter have been noted in the field experiments. Total yield ranged from 5923.8 to 12888.9 kg ha-1 at the Ödemiş location, while it was 3363.3-5009.2 kg ha-1 at the Menemen location. In conclusion, the highest yield is taken from F2 in both plant densities in Ödemiş. In Menemen, the highest yield is taken from the dose of F3 (80 kg Nha-1) and F4 (120 kg Nha-1).

This study, conducted at Ege University, Odemis Vocational School, aimed to investigate the influence of poultry manure applications on the nutrient, sucrose, fructose, and glucose content of second crop onions. In this research, three onion varieties (Burgaz, Snow White, Champion), three different doses of poultry manure (20, 40, 60 t ha−1), and mineral fertilizer were employed. An unfertilized plot was employed as the control. The experiment was designed using a split-split plot arrangement and replicated three times. The analysis comprised the assessment of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) contents in samples collected from both onion leaves and bulbs. In addition, sucrose, fructose, and glucose levels in the bulb were determined. The Snow White variety contains the highest level of fructose, sucrose, and glucose compared to other varieties. In the exploration of the impact of macro-micro element contents in bulbs, the Champion variety exhibited significantly higher levels of N, Ca, Fe, and Cu compared to other varieties. Additionally, P, K, and Na contents were significantly higher in Champion and Snow White varieties compared to Burgaz bulbs. The difference between the applications of these nutrients was insignificant except for N, P, Na, and Fe. The Nitrogen, Potassium, Sodium, and Iron contents of soils were the lowest control, while the highest dose application had the highest value at 60 t ha−1 dose. The difference among the applications in these nutrients was significant except for Mg and Cu. It may be recommended to use 40 t ha-1 dose in onion cultivation.