| Rice is a staple food to many countries and over half of the earth’s entire population depends on rice.Despite the fact that rice agriculture and its activities are liable for human existence and economic development there are no extra lands for its cultivation.Rice production is at the risk of paddy contamination with heavy metals.In modern agriculture,many heavy metals that cause pollution of agricultural products and soil have been classified as carcinogens,which has become a serious problem that has attracted people’s attention.Its remediation is essential for wholesome and sustainable crop production but most of the processes are long and costly.The application of biochar has been found to improve soil fertility through its enhanced nutrient retention leading wholesome to increased nutrient uptake and consequently increased crop yield.This study “Effects and Interaction of Cadmium and Biochar on Rice Plant”,therefore is focused on assessing the single and interactive effects of cadmium and biochar on the growth,yield,and nutrient uptake of the rice plant.Also the effects on the soil properties and the potential of using corn straw biochar to mitigate these effects.Soil samples for the study were collected from an experimental plot of the College of Plant Science,Jilin University,and some physio-chemical properties of the soil were determined before applying the soil treatments.Pot experiments involving 4 levels of cadmium 0 mg,20 mg,40 mg and 100mg/pot and 6 doses of biochar at 0 t/ha,5 t/ha,10 t/ha,20 t/ha,40 t/ha and 80 t/ha were designed.Growth parameters such as weekly plant height were monitored one week after transplanting to harvesting.After harvest,the biomass,the grain yield and plant nutrient concentrations were determined.Residual soil analysis was carried out after harvest.The results of the study obtained are as follows:1.Plants in soils with only biochar added generally recorded higher plant heights within eight weeks,while soils with cadmium(without biochar)had the lowest plant heights.Within a certain range,the height of rice plants increased with the increase of biochar content,indicating that the addition of biochar is beneficial to increase the plant height of rice.2.Adding biochar to the same cadmium-contaminated soil increased the rice stem height by 380.98%.The weight of rice plant leaves and plant root weight decreased with the increase of soil cadmium content.Compared with the case of adding biochar,in spiked soils with different levels of cadmium(20,40,100 mg / pot),the grain quality of rice ears decreased by 67.7%,92.8%,and 92.5%,respectively.3.Adding biochar to cadmium-contaminated soil increased the number of grains,grain weight,and yield of rice.When the cadmium content in the soil is 20 mg / pot,the yield per pot increases by 121.60,90.16,115.32,107.63 and 141.39 g respectively;when the cadmium content in the soil is 40 mg / pot,the yield per pot increases by 124.08,92.97,103.97,113.33 and 88.77 g,respectively;When the cadmium content in the soil is 100 mg / pot,the yield per pot increases by 41.74,51.55,70.98,48.14 and 79.58 g,respectively.4.Plants recorded minimum nitrogen uptake values when biochar was applied at 20t/ha,5t/ha and 5t/ha to 20,40 and 100mg/pot cadmium respectively.The uptake values were 66.45 mg,8.62,47.80mg/pot respectively which were all higher than when there was no biochar amendment.5.When biochar was added to the cadmium only spiked soils there was a decrease of 10.62mg/kg,16.41mg/kg and 33.16 mg/kg in the concentration of cadmium for 20,40 and 100mg/pot when 40,80 and 20t/ha biochar was applied respectively.6.Finally,the total nitrogen increased to 1.85g/kg when biochar was applied at 80t/ha with no cadmium.This was 45.03% different from when there was no cadmium and no biochar.This was also 50.27,61.17 and 50.02% different when compared to the cadmium soils with 20 40 and 100mg/pot cadmium. |
PDF Full Text Request