Biochar has attracted significant attention due to the long-lasting nature, and prominent influence on soil characteristics. This study was conducted to evaluate changes in the activity of β-glucosidase enzyme (BG) in loamy and sandy loam texture soils following two winter wheat growing seasons. The experimental design was a randomized complete block with three replicates and four treatments. The treatments were two soils, three biochars (rice husk, corn cob and bean harvest residue), five biochar rates (BR) and five levels of mineral fertilizers (FR) or dairy effluent (DE). The fertilizers were applied at the beginning of each season, while biochars were applied only at the beginning of experiment. Soil samples were collected following the second season and analyzed for the BG activity. Addition of biochars reduced the BG activity and the decline was higher in sandy loam compared to loamy soils. Negative effect of biochar to BG activity was greater at the highest BR (3.0%) than the lower BR. Fertilizer additions along with DE biochar had significant effect on BG activity that increased with higher FR. Given the importance of BG activity in soil organic matter decomposition, biochar application can be considered a sustainable way of increase in carbon sequestration.

Abiotic stresses caused by cadmium (Cd) contamination in soil retard plant growth and decline the quality of food. Amendment of biochar was reported effective in reduction of mobility, plant uptake and toxicity of Cd in plants. The aim of this study was to investigate the effect of biochar applications produced from corn cob and rice husk at three different pyrolysis temperatures (400, 500 and 600 °C) on Cd uptake of tobacco plants. The results showed that the shoot Cd concentration and content of tobacco plants significantly increased with the application of Cd in increasing doses. The results showed that increasing Cd dosescaused significant increase (P < 0.01) in shoot Cd concentration and content of the tobacco plant at three different pyrolysis temperatures of both corn cob and rice husk biochars. The concentration of Cd was 0.48 mg kg−1 in Cd0 dose of corn cob biochar produced at 500 °C and increased to 61.6 mg kg−1 at Cd5, while Cd concentration increased to 72.3 mg kg−1 with rice husk biochar. Despite the increase in Cd concentrations and content, shoot Cd concentrations and contents were significantly (P < 0.01) reduced with the treatments of corn cob and rice husk biochars produced at different pyrolysis temperatures. The Cd concentration at Cd5 dose in the absence of biochar addition was 90.5 mg kg−1, while Cd concentration at Cd5 dose in 400, 500 and 600 °C treatments of corn cob biochar was reduced to 66.5, 61.6 and 67.3 mg kg−1 respectively, and to 77.0, 72.3 and 70.2 mg kg−1 in rice husk biochar. The results also revealed that corn cob biochar treatments were more effective in reducing Cd uptake of tobacco plants compared to rice husk biochar. Higher specific surface area of corncob biochar compared to rice husk biochar caused to the difference between two biochar sources on Cd uptake of tobacco plants.

The increasing presence of microplastics (MPs) and cadmium (Cd) in agricultural soils represents an emerging environmental challenge, necessitating urgent investigation due to their potential synergistic effects on soil and plant health. This study investigated how polyethylene microplastics (PE-MPs) affect Cd behavior in soil, focusing on both their individual and combined impacts on soil pH, Cd bioavailability, plant growth, and nutrient dynamics. MPs can act as carriers of Cd, enhancing its mobility within the soil–plant system. To achieve this, a pot experiment was conducted using soils treated with different doses of PE MPs (0%, 1%, and 2%, w/w) and Cd (20 mg Cd kg⁻¹). Soil pH, DTPA-extractable Cd, plant growth parameters, Cd accumulation in roots and shoots, and mineral nutrient concentrations were measured. The results indicated that while Cd alone did not significantly alter soil pH, increasing MP doses statistically reduced soil pH and enhanced Cd bioavailability, with DTPA-extractable Cd rising by 14.4% to 25.4%. The combined application of MPs and Cd resulted in a 38% reduction in root yield and a 32% decrease in above-ground biomass. The presence of MPs exacerbated Cd uptake, leading to significantly higher Cd accumulation in both roots and shoots compared to Cd application alone. Moreover, the combined presence of MPs and Cd disrupted the nutrient uptake mechanisms, as evidenced by significant reductions in nitrogen (N) and phosphorus (P) concentrations in root and shoot tissues. These results indicate that MPs and Cd together disrupt soil chemical stability and compromise plant nutritional status. Thus, our findings emphasize that MPs not only serve as physical pollutants but also as vectors that intensify heavy metal contamination risks in agricultural ecosystems. Graphical Abstract

In this study, effects of foliar Zn sprays at different periods on yield, fruit quality attributes, bioactive compounds and micro-macro elements of ‘Granny Smith’ (Malus x domestica Borkh.) apples grafted on MM111 rootstocks were investigated. Experimental treatments were arranged as control (without Zn sprays), Zn-1 [Zn sprays 1 month after full bloom (when the fruit had a size of a walnut)], Zn-2 (Zn sprays 1 and 2 months after full bloom) and Zn-3 (Zn sprays 1, 2 and 3 months after full bloom). Experimental trees were sprayed with 0.2% Zn (ZnSO₄.7H₂O). Compared to control, Zn sprays increased yields. SSC values of Zn-2 and Zn-3 treatments were lower than the control and Zn-1 treatments. The total phenolics and total flavonoids of Zn-treated fruit were lower than the control fruit. The greatest vitamin C and antioxidant activity were obtained from Zn-2 and Zn-3 treatments, respectively. Zn-2 and Zn-3 treatments had greater zinc and phosphorus concentrations than the control treatments and Zn-sprayed fruit had greater nitrogen and potassium concentrations than the control fruit. It was concluded based on present findings that Zn treatments could be used as an effective tool to increase yield, antioxidant activity and mineral elements of ‘Granny Smith’ apples.

Cadmium (Cd) accumulation in durum wheat (Triticum durum L.) and its human transport with food chain is a major environmental issue worldwide. The research was based on a pot experiment conducted on fifteen durum wheat cultivars, grown on acid soil pH 5.2. The effect of application of two different lime form (lime1=CaO; Calcium oxide and lime2=CaCO3; limestone) and on shoot dry weight and shoot concentrations of cadmium (Cd). Durum wheat cultivars were grown in strongly acid soil pH 5.2 treated with control (lime0), lime1 (CaO3 g kg-1 soil), lime2 (5.36 g CaCO3) and Cd (5 and 10 mg kg-1 soil) and harvested after 62 days of growth under greenhouse conditions. Durum wheat cultivars without lime fertilization caused decrease in shoot growth, in all durum wheat cultivars and at high Cd treatment. On the other hand, application of lime to the soil resulted in an increase in dry matter yield at both Cd5 and Cd10 doses. While average shoot dry matter yield of lime0 conditions of cadmium 10 dose was 47 mg plant-1, this yield increased to 120 mg plant-1 in lime1 application and to 111 mg plant-1 in lime2 application. Shoot Cd concentrations of durum wheat varieties caused a statistically significant decrease with lime1 and lime2 applications, whereas lime0 and lime2 applications of Cd5 dose caused 46% and 30% decrease in average Cd concentrations, respectively. The results indicated that all durum wheat cultivars were more susceptible to both without lime and Cd toxicity as compared to lime treatment. Cadmium toxicity in the shoot was relieved by lime1 and lime2 treatment. The results indicate that lime protects plants from Cd toxicity in durum wheat cultivars.

Besin elementlerinin kök bölgesi altına yıkanmasının engellenerek toprakta daha uzun süre tutunmaları gübrenin etkinliğinin artması anlamına gelir. Kök bölgesinin altına inen besin elementleri, hem bitki için yarayışsız hale gelmekte hem de yer altı sularına karışarak kirlenmelerine ve ekosistemin fonksiyonlarına zarar vermektedir. Bu çalışma, orta bünyeye sahip bir toprağa farklı dozlarda ilave edilen domates hasat atıklarının 500 °C’de yavaş piroliz edilmesi ile hazırlanmış biyokömür materyallerinin, nitrat (NO 3 - ) ve amonyum (NH 4 + ) yıkanmalarına etkinlerini test etmek için yapılmıştır. Üç farklı biyokömür dozu (%1, %3 ve %6) ve kontrol uygulamalarını kapsayan 3 tekerrürlü yıkama çalışmaları, 35 cm uzunluğundaki PVC borularında yapılmıştır. Şeker pancarının 60 ton ha -1 verimi için kullanılan toplam azot (240 kg N ha -1 ) ve su miktarları (875 mm) uygulanmıştır. Toplam su, altı defa da damla şeklinde verilmiştir. Her sulama döneminde sızan su toplanmış ve NO 3 - ve NH 4 + konsantrasyonları ile pH ve elektriksel iletkenlik (EC) değerleri için analiz edilmiştir. Yapılan istatiksel değerlendirme sonucunda, sızan suyun NO 3 konsantrasyonu açısından uygulamalar arasında önemli farklılık olmasına rağmen, NH 4 yıkanmasına uygulamaların etkisi önemsiz bulunmuştur. Nitrat yıkanmasını en fazla azaltan uygulama, kontrole göre %34.5 daha az olan %3 biyokömür olmuştur. Yıkamalar sonunda kolonlarda en yüksek nitrat konsantrasyonuna sahip uygulama 9532 mg kg -1 ile %6 dozunun olduğu uygulamadır. En düşük NO 3 - konsantrasyonu ise 6950 mg kg -1 ile %0 dozu ile kontrollerdir. Çalışma sonuçları, biyokömür uygulamaları ile azotun (özellikle NO 3 - ) kök bölgesinde daha uzun süre yıkanmadan tutunabileceğini göstermiştir.