Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the e...Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA derived from lignite on growth and macronutrient uptake of wheat （Triticum acstivum L.） grown in earthen pots under greenhouse conditions. The soils used in the pot experiment were a calcareous Haplustalf and a non-calcareous Haplustalf collected from Raisalpur and Guliana, respectively, in Punjab Province, Pakistan. The experiment consisted of four treatments with HA levels of 0 （control without HA）, 30, 60, and 90 mg kg^-1 soil designated as HA0, HA1, HA2, and HA3, respectively. In the treatment without HA （HA0）, nitrogen （N）, phosphorus （P）, and potassium （K） were applied at 200, 100, and 125 mg kg^-1 soil, respectively. Significant differences among HA levels were recorded for wheat growth （plant height and shoot weight） and N uptake. On an average of both soils, the largest increases in plant height and shoot fresh and dry weights were found with HA2 （60 mg kg^-1 soil）, being 10%, 25%, and 18%, respectively, as compared to the control without HA （HA0）. Both soils responded positively towards HA application. The wheat growth and N uptake in the non-calcareous soil were higher than those of the calcareous soil. The HA application significantly improved K concentration of the non-calcareous soil and P and NO3-N of the calcareous soil. The highest rate of HA （90 mg kg^-1 soil） had a negative effect on growth and nutrient uptake of wheat as well as nutrient accumulation in soil, whereas the medium dose of HA （60 mg kg^-1 soil） was more efficient in promoting wheat growth.展开更多
Root and shoot growth of Brassica campestris L. and B. juncea increased significantly （P 〈 0.01） with enhanced Ca2＋ treatment along with 60 mM NaCl in the root medium. The maximum fresh mass of shoot and root in B...Root and shoot growth of Brassica campestris L. and B. juncea increased significantly （P 〈 0.01） with enhanced Ca2＋ treatment along with 60 mM NaCl in the root medium. The maximum fresh mass of shoot and root in B.juncea was recorded at 10 mM Ca2＋ concentration. The relative growth rate of shoot of both species reached its maximum at 8 mM of Ca2＋ concentration. Average rate of Ca2＋ intake （lCa） was higher in B. juncea than 6. campestris. In B. juncea, the average transport of Ca2＋ to shoot increased by 19%, 38%, 119%, 125% and 169% compared with the control. Furthermore specific utilization rate of Ca2＋ was higher in B. juncea than B. campestris. In B. campestris it increased by 9%, 32%, 41% and 59% at 4, 6, 8, and 10 mM of calcium in comparison to 2 mM Ca2＋ treatment. At 4, 6, 8 and 10 mM of Ca2＋ application, the increase in the leaf area ratio was 10,17, 23 and 30%, respectively. In the shoot and root portions of B. campestris and B.juncea, Ca2＋ had a linear relationship with potassium and sulfur, whereas it was in antagonism with sodium ion.展开更多
基金Supported by the University of Azad Jammu and Kashmir,Muzaffarabad,Pakistan
文摘Humic acid （HA）, a fairly stable product of decomposed organic matter that consequently accumulates in ecological systems, enhances plant growth by chelating unavailable nutrients and buffering pH. We examined the effect of HA derived from lignite on growth and macronutrient uptake of wheat （Triticum acstivum L.） grown in earthen pots under greenhouse conditions. The soils used in the pot experiment were a calcareous Haplustalf and a non-calcareous Haplustalf collected from Raisalpur and Guliana, respectively, in Punjab Province, Pakistan. The experiment consisted of four treatments with HA levels of 0 （control without HA）, 30, 60, and 90 mg kg^-1 soil designated as HA0, HA1, HA2, and HA3, respectively. In the treatment without HA （HA0）, nitrogen （N）, phosphorus （P）, and potassium （K） were applied at 200, 100, and 125 mg kg^-1 soil, respectively. Significant differences among HA levels were recorded for wheat growth （plant height and shoot weight） and N uptake. On an average of both soils, the largest increases in plant height and shoot fresh and dry weights were found with HA2 （60 mg kg^-1 soil）, being 10%, 25%, and 18%, respectively, as compared to the control without HA （HA0）. Both soils responded positively towards HA application. The wheat growth and N uptake in the non-calcareous soil were higher than those of the calcareous soil. The HA application significantly improved K concentration of the non-calcareous soil and P and NO3-N of the calcareous soil. The highest rate of HA （90 mg kg^-1 soil） had a negative effect on growth and nutrient uptake of wheat as well as nutrient accumulation in soil, whereas the medium dose of HA （60 mg kg^-1 soil） was more efficient in promoting wheat growth.
文摘Root and shoot growth of Brassica campestris L. and B. juncea increased significantly （P 〈 0.01） with enhanced Ca2＋ treatment along with 60 mM NaCl in the root medium. The maximum fresh mass of shoot and root in B.juncea was recorded at 10 mM Ca2＋ concentration. The relative growth rate of shoot of both species reached its maximum at 8 mM of Ca2＋ concentration. Average rate of Ca2＋ intake （lCa） was higher in B. juncea than 6. campestris. In B. juncea, the average transport of Ca2＋ to shoot increased by 19%, 38%, 119%, 125% and 169% compared with the control. Furthermore specific utilization rate of Ca2＋ was higher in B. juncea than B. campestris. In B. campestris it increased by 9%, 32%, 41% and 59% at 4, 6, 8, and 10 mM of calcium in comparison to 2 mM Ca2＋ treatment. At 4, 6, 8 and 10 mM of Ca2＋ application, the increase in the leaf area ratio was 10,17, 23 and 30%, respectively. In the shoot and root portions of B. campestris and B.juncea, Ca2＋ had a linear relationship with potassium and sulfur, whereas it was in antagonism with sodium ion.
