The Pedospheric Variation of DTPA-Extractable Zn, Fe, Mn, Cu and Other Physicochemical Characteristics in Major Soil Orders in Existing Land Use Systems of Punjab, India

Abstract

The agricultural production in Punjab has increased manifold that aggravated the deficiencies of micronutrients in soils and plants. The availability of soil micronutrients in different soil orders depends upon the soil mineralogy, topography, climatic conditions and cropping sequences. Hence, to study the pedospheric variations of DTPA-extractable micronutrients, viz., zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu), in three prominent soil orders of Punjab, a total of 144 depth-wise soil samples were collected from four major land-use systems (cultivated, horticulture, forest and pasture lands). The DTPA extractable micronutrients varied from 1.74–2.81, 1.83–2.82 and 1.81–2.80 for Zn; 5.3–6.8, 5.6–6.9, 4.3–6.3 for Fe; 5.1–7.8, 5.5–7.9, 5.4–7.5 for Mn; and 0.84–1.40, 0.93–1.68, 0.87–1.65 for Cu in soil orders Aridisol, Entisol and Inceptisol, respectively. The average content of DTPA-extractable micronutrients was highest under soil order Entisol followed by Inceptisol and Aridisol. The content of micronutrients showed a declining trend with increase in soil depth in all orders. Among different soil properties, the pH and EC showed significantly negative correlation, however, OC had non-significant correlation with DTPA-extractable micronutrients in soils. Therefore, it is concluded that parent material, land use systems and soil depth affected the distribution of DTPA extractable micronutrients in different soil orders.

Soil Fertility Status under Soils of Sugarcane-Ratoon-Wheat Cropping System of Meerut District of Uttar Pradesh, India

“…The results revealed that the distribution of DTPA-Cu slightly decreased with increasing depth. The fact that organic matter in the form of crop residues has been added to the surface layer of soils, reducing pH, may be the cause of the greater Cu content on surface soils [13]. The soils under this cropping system were sufficient in available copper content.…”

“…Mean values of CEC 15.96, 13. 13 , DTPA Mn 8.20, 6.80 and 5.20 mg kg -1 and DTPA Cu 0.99, 0.74 and 0.56 mg kg -1 were recorded at 0-15 cm, 15-30 cm and 30-45 cm, respectively. Soils under this cropping system were low in available nitrogen content and medium in available phosphorus and potassium content.…”

“…Soil available potassium content was ranged from 131.04-185.92, 89.60-141.12 and 87.36-126.56 kg ha -1 at 0-15 cm, 15-30 cm and 30-45 cm with mean values of 156.43, 118.16 and 102.11 kg ha -1 , respectively. The greater content of available K may be due to the governance of K-rich minerals and also the addition of OM that helped in the replenishment of nutrient status in soil [13]. However the soils under this cropping system were low in available K status.…”

“…Soils under sugarcane-ratoon-wheat cropping systems were sandy clay loam to clay loam. The greater clay content was observed that might be due to the higher stratified nature of these soils [13]. Soils under this cropping system possess a finer texture, i.e., higher clay corresponds to more organic matter addition and higher microbial activity, thereby improving soil fertility and more productivity as compared to undisturbed land-use systems [14].…”

“…, respectively. The higher the concentration of organic matter in soils, the greater the amount of DTPA extractable Fe in surface soil layers [13]. The higher Fe content might also be attributed to the increased input of organic residues, which improved soil aeration, provided chelating agents, and reduced Fe precipitation and oxidation, improving the availability of micronutrients in soils [24,25].…”