Xorazm ma ’ mun akademiyasi axborotnomasi – /2020 Ўзбекистон республикаси фанлар

XORAZM MA
’
MUN AKADEMIYASI AXBOROTNOMASI 
–
9/2020
25
Pot Experiment. 
After the soil was air-dried, it was passed through a 2 mm sieve. Air-dried 
soils (2 kg per pot) were placed in plastic pots (height: 25 cm; diameter: 25 cm). Moisture was 
maintained at 
∼
60% of the maximum water-holding capacity to balance one week. And then the 
moisture was maintained at 
∼
80% of the maximum water-holding capacity. No fertilizers were 
added throughout the experiment. In the control treatment, there was no plant in the pot. Before the 
seed germination, 1269 seeds of the same size were selected in each pot. After 7 days, the seedlings 
were planted to ensure that 472-756 germination seeds were planted in each pot. 
Sampling and Analysis. 
Soil moisture was determined gravimetri
cally in fresh soils at 105°C 
to constant weight. Soil pH of air-dried samples (sieved to 1 mm) was determined using the glass 
electrode with a soil to water (non-CO
2
deionized water) ratio of 1:2.5. Soil organic matter (SOM) 
was analyzed using the ISO method. Soil heavy metals contents were determined by using atom 
adsorption spectrometry. Plants were harvested after 323 days, and the fresh shoots and roots were 
harvested separately. Fresh shoots and roots from each treatment were immediately stored at −80°C 
for weigh. 
Results and discussion 
Table 1 provides soil physical-chemical properties and heavy metal concentration before 
reclamation. As the result soil condition is neutral, Soil organic matter (SOM) is 4.8 which is higher 
than other soils, and total concentration of heavy metals are more than MPA. Soils in Uzbekistan 
MPA limit of Pb and Zn are 32 and 23 respectively, due to soil condition [8]. 
Table 1.
Soil physical-chemical properties and heavy metals concentration before reclamation