Feyzullah Öztürk

The soybean plant, with its high protein and oil content, plays a vital role in both human nutrition and animal feed, and is a strategic agricultural product, particularly due to its ability to fix nitrogen in the soil. The application of various long-term sources, such as mineral fertilisers, compost, manure, and mycorrhiza, plays a significant role in increasing soybean yield by directly affecting both the plant's productivity and carbon sequestration in the soil. The experiment was established in 1996 within the Soil Science and Plant Nutrition Research Area of the Research and Application Farm at Çukurova University's Faculty of Agriculture, utilising a randomised block design. The current research began with Soybean (Glycine max (L.) Merr.) cultivation in the 2022-2023 production year. Before cultivation, control, mineral fertilizer (NPK), animal manure (25 tons ha-1), compost (25 tons ha-1), and compost + mycorrhiza (10 tons ha-1) were applied. After harvest, different parts of the soybean were harvested. The nutrient content of different parts of the soybean plant was analyzed. Total, inorganic and organic carbon concentrations in the soil were investigated. Also, CO2 fixation through photosynthesis was determined. The highest grain yield and total biomass were found in soybean plants treated with compost application. In general, compost, compost+mycorrhiza, and subsequently manure applications produced higher yields and biomass than mineral fertilizer and control plots in the soybean plant environment. Additionally, total carbon concentration and total CO2 fixation in the soil were highest in the compost application. The total organic carbon (TOC) in the soil was highest following manure application. Agricultural sustainability and carbon sequestration in soil are recommended for further research to mitigate the potential negative effects of climate change through the use of manure, compost, and mycorrhizae. Future studies should examine the impact of these applications under different plant species and soil types. These findings could play an essential role in shaping environmental policies related to carbon sequestration, the carbon cycle, and soil health.

Soybeans, as an industrial plant, are used in many industries. Since soybeans fix nitrogen through the rhizobium bacteria, P fertilization is one of the biggest requested fertilizers in their production. In this context, under long-term experimental conditions, the aim is to investigate the effect of increasing doses of P application on soybean yield and nutrient uptake. The hypothesis is that optimum P fertilizer doses increase soybean yield and P uptake. A field experiment was established in 1998 on the soil Arık soil series. Four doses of P fertilizers were applied, such as 0, 50, 100, and 200 kg P2O5 ha-1 with three replications before each cultivation term. Arısoy soybean (Glycine max L.) species seeds were sown in May 2024 and harvested in November 2024. At harvest, root, shoot dry weights, and yield were determined. Plant mineral nutrients (K, P and Zn) concentrations were analyzed by ICP-OES. ANOVA statistical analysis was realized by the JMP 8-pack program, and the less significant difference (LSD) test was carried out. Research results have shown that there is no significant difference in root dry matter and yield, but there is a significant difference in shoot dry matter yield. Especially when soybean grain yield was examined yield increased due to increasing doses from P0 to P200 (1596, 2390, 2431 and 2512 kg ha-1) fertilization, respectively. Furthermore, increasing doses of P fertilization statistically increased grain P concentration in a linear manner. Overall, for soybeans, 100 kg P2O5 ha-1 phosphorus fertilization is given an optimum dose for optimum growth. It was determined that the 100 kg P2O5 ha-1 application is the optimum application in soybean cultivation growth and nutrient uptake under long-term field experiments.

Different long‐term tillage systems were examined for their effects on the amount of native mycorrhizal spores in the rhizosphere and nonrhizosphere soils, as well as their effects on the organic carbon and mineral nutrient content of the soil. The long‐term study was initiated in 2006, using a Typic Haploxerert soil series, with the current study conducted in 2018–2019 using the Adana‐99 wheat variety. Seven tillage systems were examined: two no‐tills (NT and ST), three reduced tillage systems (RT‐1, RT‐2, and RT‐3), two conventional tillage systems (CT‐1 and CT‐2), and one strategic/occasional tillage system with three replicates as randomized blocks. The effects of tillage management on soil quality parameters were found by analyzing N, P, K, Mg, Ca, Cu, Fe, Zn, and Mn contents, as well as inorganic and organic carbon in soil samples taken before sowing and postharvest. Tillage systems had a significant influence on mineral nutrient concentrations. Reduced and no‐tillage methods, particularly strategic and no‐tillage, contribute positively to soil organic carbon (SOC) sequestration and nutrient retention and the number of mycorrhizae spores. The results show that as the tillage intensity decreased, the soil C, N, K, Ca, and Mg contents increased mycorrhizal spores. The rhizosphere soils under no‐tillage and reduced tillage practices had higher soil carbon content and higher mycorrhizae spore counts at the postharvest stage than soils under conventional tillage (CT) practices. Conclusively, after 13 years of different soil tillage treatments, more carbon was sequestrated under NT than under heavy tillage CT treatment. The ST tillage treatment sequestrated 19.37 Mt SOC (0–15 cm) and 10.06 (15–30 cm) Mt SOC compared with the CT‐1 tillage treatment. Comparing CT treatments, RT tillage and NT maintained higher carbon concentrations of up to 17% and 31%, respectively.

Çalışmanın amacı uzun süreli çakılı deneme koşullarında artan dozlarda P uygulamasının toprak C, N ve P içeriği ve elementlerin kendi aralarındaki etkileşimlerini araştırmaktır. Test edilen araştırma hipotezi ise; artan dozlarda P uygulaması toprak C, N ve P konsantrasyonlarını arttırmakta ve buna bağlı olarak bitkisel üretim artmaktadır. Deneme Çukurova Üniversitesi Ziraat Fakültesi Araştırma ve Uygulama Çiftliğinde 1998 de Arık toprak serisinde çakılı deneme olarak kurulmuş ve günümüze kadar buğday-mısır rotasyonu olarak devam ettirilmektedir. Söz konusu çalışmada her üretim sezonu öncesi 0 kg P2O5 ha-1 (P0), 50 kg P2O5 ha-1 (P50), 100 kg P2O5 ha-1 (P100) ve 200 kg P2O5 ha-1 (P200) konuları üç tekerrürlü olarak uygulanmaktadır. Çalışma Kasım 2017 de Adana-99 çeşidi Buğday (‎Triticum aestivum L.) ekilerek kurulmuş olup Mayıs 2018 de hasat edilmiştir. Hasat ile birlikte farklı toprak derinliklerinden (0-15 ve 15-30 cm) ve farklı bölgelerden (rizosfer ve rizosfer olmayan) toprak örnekleri alınarak analize hazır hale getirilmiştir. Toprak organik C (OC), inorganik C (IC), toplam C ve N içeriği ve P konsantrasyonları tayin edilmiştir. Araştırma Bulguları gösteriyor ki; her iki derinlikte rizosfer (R) ve rizosfer olmayan (NR) bölgelerde P içeriği bakımından istatistiksel olarak dikkate değer bir fark olup; kontrole kıyasla en iyi uygulama P200 uygulamasında elde edilmiştir. Artan P doz uygulaması ile toprak P içeriği doğrusal bir şekilde artmıştır. Toprak OC içeriği bakımından ise rizosfer ve rizosfer olmayan bölgelerde (15-30 cm derinlikte) istatistiksel olarak dikkate değer bir fark olup, kontrole kıyasalar en iyi uygulama P200 uygulamasında sağlanmıştır. Ayrıca, artan P doz uygulamasına bağlı olarak ortalama toprak OC, toplam N ve C içeriği artış göstermekte olup sonuçlar hipotezimizi destekler niteliktedir.