Soil Fertility Status of Forage Growing Soils of Nalgonda District, Telangana
Author: R. Hima Bindu, T. Sukruth Kumar, T. Anjaiah, R.V.T. Balazzii Naaiik and T. Shashikala
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Abstract
In Telangana 4,58,892 acres of land is under fodder crops. In which 4,54,874 acres under annual fodders and 4,018 acres under perennial fodders. In this approximately 20 % of the state forage crop cultivating area is observed in erstwhile Nalgonda district (92,230 acres) with high livestock population. Till now fertility status studies on forage growing soils were limited. So it is highly essential to study the fertility status of forage growing soils and the quality of fodder in Nalgonda district. Livestock are an important asset and livelihood option for poor people in rain fed areas. Fodder crops are the plant species that are cultivated and harvested for feeding the animals in the form of forage, silage and hay. A survey was carried out in forage growing soils of Nalgonda district of Telangana state. Seventy five representative surface soil samples (0-15 cm) were collected and analysed for their salient characteristics viz., pH, EC, OC, free CaCO3, available N, P2O5, K2O and micronutrients (Zn, Fe, Cu and Mn). Soil fertility maps were prepared for macronutrients. Results revealed that, soil pH ranged from 5.68 to 8.34. The soils were non-saline to slightly saline (0.06 to 1.12 dSm-1). The organic carbon ranged from 0.85 to 12.03 g ka-1. Free Calcium Carbonate content ranged from 1.22 to 22.41per cent. With regard to available nutrients, the values varied from 104.0 to 230.2 kg N ha-1 for nitrogen, 8.0 to 92.6 kg P2O5ha-1 for phosphorus, 91.9 to 399.6 kg K2O ha-1 for potassium. Among the micronutrients 14.6 and 10.6 percent soils were deficient in available zinc and iron. Deficiency of Cu and Mn were negligible.
Keywords
N, P2O5, K2O, Zn, Fe, Cu and Mn
Conclusion
1. The soils of Nalgonda district are alkaline in reaction and very little were acidic. 68 % soils are low in organic carbon and only 6.6 % soils are high in Organic carbon content.
2. Electrical conductivity of soils in Nalgonda district ranged from 0.06-1.12 dSm-1 and about 38.6 % soils were high in calcium carbonate content.
3. Nitrogen content were low in 100 % samples collected from Nalgonda district The available N ranged from 104.0 to 230.2 kg N ha-1.
4. The available phosphorus content ranged from 8.0 to 92.6 kg P2O5ha-1.
38.6 % of samples collected in the district has shown lower phosphorous content and 32.0 % samples are medium in phosphorous in content. It shows 29.4 % of soils in the district were medium to high in phosphorous level.
5. The available potassium content of the soils varied from 91.9 to 399.6 kg K2O ha-1.92% samples in the district are medium to high in potassium content.
6. In Nalgonda district 14.6 % samples are deficient in Zinc nutrient, while the other micro nutrient like cu and Mn are sufficient in soils and Fe is deficient in 10.6 % soils.
7. Deficiency levels in micro nutrient content in Nalgonda district follows Zn>Fe>Mn>Cu.
References
INTRODUCTION
In India the total area under cultivated fodders is 8.3 million ha on individual crop basis. Sorghum amongst the kharif crops (2.6 million ha) and Berseem (Egyptian clover) amongst the rabi crops (1.9 million ha) occupy about 54% of the total cultivated fodder cropped area. Lucerne (Alfa alfa) occupies highest productivity (60-130 tonnes ha-1).
In Telangana, total area under fodder crops cultivation is 4,58,893 acres during the year 2020-21(GOI, 2021) Telangana state has very rich livestock resources. The total livestock population of the State is 264.5 lakhs, in which 48.8 lakh buffaloes, 128.3 lakh sheep and 45.7 lakh goats. As per the 20th livestock census (2017) which is 4.6% over the year 2012.
Generally, fodder crops were grown in marginal to medium fertile soils. Quality of fodder (Protein and Fibre content) depends on the fertility of soils. Fertile soils produce high quality fodder. Feeding the quality green fodder to dairy animals yields high milk and meat production.
In Telangana approximate 20% of the state area is under fodder crops (92,230 acres) observed in erstwhile Nalgonda district with high livestock population (GOI, 2021). So it is highly essential to study the fertility status of the fodder growing soils of Nalgonda district. This paper deals with nutrient status (Physico-chemical and chemical properties) of forage growing soils of Nalgonda district.
MATERIAL AND METHODS
Study Area and Sample Collection. The soil survey was carried out representing the forage growing soils of the Nalgonda district (Fig. 1). A total of Seventy five soil samples (0-15 cm depth) were collected.
The soil samples were collected using GPS (Global Positioning System) and the longitude and latitude points of a particular location were recorded (Fig. 2). The soil fertility maps for N, P2O5 and K2O were prepared with the help of Q.GIS.3.22.9 software using GPS points. The soil samples were packed and labelled properly in polythene bags and brought to the laboratory for further analysis.
Laboratory Analysis. All the soil samples were air dried, grounded and passed through 2 mm sieve for chemical analysis. The soils were analysed for salient characteristics viz., pH, EC, OC and free CaCO3 & available nutrients (N, P2O5, K2O, Zn, Fe, Cu and Mn) following standard procedures. After analysis for available nutrient status, the soils were categorised as low, medium and high for N, P2O5 and K2O. The available sulphur and micronutrients (Zn, Fe, Cu and Mn) were rated as deficient and sufficient based on the critical levels as given by Tandon (2005).
RESULTS AND DISCUSSION
Physico-chemical Characteristics. Soil reaction (pH) of the surface soils ranged from 5.68 to 8.34 indicating that, these soils are slightly acidic to alkaline in reaction. The observations on the soil pH revealed that, 2.66 percent of soils were slightly acidic (<6.5) in nature, 52 per cent samples are neutral (6.5-7.5) and 45.34 percent samples are alkaline (>7.5) in nature.
Electrical conductivity (EC) of surface soils ranged from 0.06 to 1.12 dSm-1 indicating that, these soils were non-saline to slightly saline in nature. The observations on EC revealed that, 96% of samples fall under the range of 0 to 1 dS m-1 remaining 4% samples fall under the range of 1 to 2 dS m-1.
With regard to the status of organic carbon (g kg-1) the values found to vary from 0.85 to 12.03 g kg-1. The observations on organic carbon revealed that, 68 % of soil samples were low (<5.0 g kg-1), 25.33% of soils were medium (5.0-7.5g kg-1) and 6.66% (>7.5g kg-1) of soils were high in organic carbon. The reason for low organic carbon content in most of the soils may be attributed to the prevalence of semi-arid condition, where the degradation of organic matter occurs at a faster rate coupled with little or no addition of organic manures and lower vegetation on the fields, there by leaving less chances of accumulation of organic carbon in the soils. Intensive cropping is also one of the reasons for low organic carbon content in soils. The similar results were also reported by Nalina et al. (2016).
Free Calcium Carbonate content (%) the values found to vary from 1.22 to 22.41per cent. About 38.6 per cent samples are calcareous in nature..The calcareous nature of soils may be due to semi-arid conditions because of relatively little leaching. Similar results were reported by Brady and Weil (1999); Brindha and Elango (2014).
Available Nutrients. The available nitrogen content of the soils ranged from 104.0 to 230.2 kg ha-1 (Table 1 and depicted in Fig. 3). Out of the 100 samples analysed, all the soil samples found to have low (<280.0 kg N ha-1) available nitrogen. From the survey data, previous history of the crops grown was taken which indicated that cotton is one of the major commercial crops grown in Nalgonda district. As cotton is a heavy nitrogen feeder which may leads to nitrogen deficiency. Another reason may be due to high temperature and low organic matter content which fasten decomposition process as a result removal of organic matter can be observed which leads to N deficiency (Karthikeyan et al., 2014).
The available phosphorus content of the soils varied extremely from one point to another point. The variation exists in between 8.0 to 92.6 kg P2O5 ha-1 (Table 1 and depicted in Fig. 4). The soils found to have low to very high available phosphorus. Among the soils analysed, 38.6, 32.0 and 29.4 per cent of soils registered low (<22.9 kg P2O5 ha-1), medium (22.9 to 56.3 kg P2O5 ha-1) and high available phosphorous (>56.3 kg P2O5 ha-1), respectively. This may be due to continuous application of DAP to crops without soil testing might have resulted in phosphorus build up and led medium to high available phosphorus status in these soils (Sathish et al., 2018). Another reason for higher P in surface soils possibly might be due to P confinement to the rhizosphere due to its immobile nature in soils (Rajeshwar and Mani 2014).
The available potassium content of the soils varied from 91.9 to 399.6 kg K2O ha-1 (Table 1 and depicted in Fig. 5). In analysed samples, about 8% samples recorded lower (<129.6 kg K2O ha-1) potassium content, 32% samples recorded medium (129.6-336) kg K2O ha-1) potassium content and 60% of soils recorded high (>336 kg K2O ha-1) available potassium content. These soils may able to maintain a sufficient or even high level of exchangeable K and provide a good supply of K to plants for many years. High available K status in surface soils could be attributed to release of labile-K from organic residues, application of K fertilizers and upward translocation of K from lower depths along with capillary rise of ground water. Similar results were reported by Pal and Mukhopadyay (1992).
Nalgonda district samples are analysed for micronutrients shown variation in the content from Soil to Soil. Zinc content which is extracted by using DTPA solution varied from 0.2 mg kg-1 to 4.2 mg kg-1 (Table 2). About 14.6 % samples are deficient in zinc content (<0.6 mg kg-1) and 85.4 % samples are sufficient in zinc content (>0.6 mg kg-1). Lower content of zinc was due to high pH values which have resulted in the formation of insoluble compounds of zinc (Tandon, 1995).
Soil samples analysed for Iron content varied from 0.5 mg kg-1 to 18.3 mg kg-1 (Table 2). About 10.66% samples are deficient in iron content (<4.5 mg kg-1) and 89.34 % samples are sufficient in iron content (>4.5 mg kg-1). Since, most of the soils are neutral to alkaline, low in organic carbon, there is a possibility of deficiency of Zn and Fe in these soils. Similar results were observed by Patil et al. (2016).
Soil manganese content extracted using DTPA solution varied from 0.2 mg kg-1 to 25.4 mg kg-1 (Table 2). About 4 % samples were deficient in manganese content (<1.0mg kg-1) and 84% samples were sufficient in manganese content (>1.0 mg kg-1). In general, calcium carbonate decreased the availabilities of micronutrients owing to their insoluble hydroxides at higher pH (Sahoo et al., 1995).
Available copper deficiency is negligible (Table 2) in all the soils collected from forage growing areas of Nalgonda district. Similar results were also reported by Surendra Babu et al. (2019).
Soil Fertility maps of Nalgonda district.
How to cite this article
R. Hima Bindu, T. Sukruth Kumar, T. Anjaiah, RVT. Balazzii Naaiik and T. Shashikala (2022). Soil Fertility Status of Forage Growing Soils of Nalgonda District, Telangana. Biological Forum – An International Journal, 14(3): 1135-1142.