Study of Physico-Chemical and Micronutrient Status of Soil, Water and Plant System of Sargodha District: Effect of Micronutrients (Zn, B) on Forage Yield and Quality of Oat and Pearl Millet

Abstract

Pakistani agriculture is largely an economic symbiosis of crop and livestock. But, scarcity of quality forage in the country has made livestock to continually suffer. The micronutrient nutrition of forage crops is important not only for increasing productivity but also for quality of the herbage produced. Pakistani soils are mostly calcareous and alkaline in reaction where availability of micronutrient is a serious problem. Therefore, a research was carried out to study (i) The physico-chemical characteristics of soil and water samples of Sargodha district (ii) Micronutrient status of soil and fodders of Sargodha district and, (iii) the micronutrients (Zn and B) effect on yield, yield components and quality of oat and pearl millet at district Sargodha. For this purpose soil, water and plant samples were collected twice a year during Kharif (summer) 2006 and rabi (winter) 2006-07. The sampling sites were uniformly distributed throughout district Sargodha. From each site, composite soil sample was taken up to 60 cm depth in the order of 0-15, 15-30, and 30-60 cm depths. These soil samples were analyzed for pH, particle size analysis, organic matter and micronutrients i.e. Cu, Zn, Mn, B and Fe. Similarly, associated fodder samples were also analyzed for these micronutrients. While ground water samples were also collected along with soil and plant samples and analyzed for EC, SAR, RSC and Cl -1 . After this, two field experiments at farmer field of Sargodha district were conducted to evaluate the response of micronutrients (Zn and B) to fodder yield and quality of oat and pearl millet. In this study, the soils of district Sargodha varied from loamy sand to silty clays, low in organic matter and alkaline in reaction (pH >7.0). In general, DTPA-extractable xivmicronutrients i.e., Fe, Zn, Cu, Mn and dilute HCl extractable B was higher in surface soil and decreased with depth. During kharif 2006, out of total analyzed soil surface samples 48, 01, 53, 03 and 41% were deficient in Zn, Cu, Fe, Mn and B, respectively. Similarly during rabi (2006-07) 47, 01, 47, 02 and 30% soil samples were deficient in Zn, Cu, Fe, Mn and B, respectively. Soil organic matter, pH and texture had strong influence on the distribution of plant available micronutrients. While correlation coefficients indicated that all micronutrients were positively correlated with soil organic matter. Soil pH had a negative and non-significant correlation with available Zn, Cu, Fe, Mn and positive but non-significant correlation with B in both summer and winter. Further, it can be amply surmised from the above data that light textured soils were mostly deficient in micronutrients (Cu, Fe, and B) as compared to heavy textured soils in summer. While in rabi, Zn availability decreased in coarse textured soils. Similarly, fodder samples were also analyzed for micronutrients (Zn, Cu, Mn, Fe and B). During kharif 2006, plant tissue analysis revealed a 29 and 31% Zn deficiency in millet and sorghum, respectively. Further, 10 and 14% sorghum samples were deficient in Fe and Mn, respectively. Likewise during rabi, only Mn deficiency was observed as 2, 15 and 6% in berseem, lucerne and oat, respectively. While only 2% berseem was found to be deficient for B. Ground water samples were also collected along with soil and plant samples to obtain a general picture of water resources of Sargodha district. Water samples that have EC< 1.0 dSm -1 are considered to be fit for irrigation. Almost 26 and 24% water samples were found to be fit in summer and winter, respectively. Whereas with respect to SAR, 46 and 50% water samples were fit (SAR<6) in summer and winter, respectively. While xv31 and 33% water samples had RSC<1.25 which indicated their suitability for irrigation purpose. In Pakistan, fodder crops are traditionally grown on soils having poor fertility and the use of micronutrients for these crops is negligible. Thus effects of micronutrients (Zn and B) on yield, yield components and quality of oat and pearl millet were studied during rabi 2007-08 (winter) and Kharif 2008 (summer). A factorial combination of three levels of B (0, 1, 2 kg ha -1 ) and Zn (0, 5, 10 kg ha -1 ) were applied. Data were noted for plant height, number of tillers per plant, dry matter yield, crude protein content, acid detergent fibre (ADF) and neutral detergent fibre (NDF). Plant height and tillers per plant showed positive and highly significant correlation with dry mater yield. The results showed that sole applications of B and Zn with their increasing levels significantly increased plant height, number of tillers per plant, dry matter yield and crude protein contents. Besides this, there was statistically non-significant effect of these micronutrients on protein, ADF and NDF of pearl millet. While there was some positive but non-significant effect on ADF and NDF contents of oat with application of these micronutrients. In the past, no survey of the micronutrient deficiencies in a large number of farmers’ fodder fields of Sargodha district has been undertaken. While, the earlier research has mostly concentrated on the major nutrients and the deficiencies of NPK have been reported to be widespread in this system. But our results demonstrate clearly that apart from water shortage and irrigation with brackish water, soil infertility is also the issue for crop production and productivity enhancement in study area. By balance fertilization, good quality fodder can be available throughout the year and ultimately we can perk up the animal productivity up to 50 per cent with existing gene pool. Further, it xviis emphasized that use of brackish water should be avoided to maintain soil health and for sustainable crop yield where good quality water is manageable. However, if the use of brackish water becomes necessary in an area where underground water may be the only source of irrigation, then such water should be used with proper management practices. In future experiments, we should also analyze micronutrient content in the harvested plant tissues after growing the fodders under these treatments. This will provide more information on how the treatments are affecting the micronutrient status of the kharif (Pearl millet) and rabi (oat) fodders when treated with extra B and Zn.