DELINEATION AND MAPPING OF SOIL CONSTRAINTS AND THEIR EFFECTS ON YIELD AND QUALITY OF MANGO (Mangifera indica L.) IN YSR DISTRICT, ANDHRA PRADESH USING REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM

Loading...
Thumbnail Image
Date
2024-05-22
Journal Title
Journal ISSN
Volume Title
Publisher
Acharya N G Ranga Agricultural University
Abstract
The present study on “Delineation and mapping of soil constraints and their effects on yield and quality of mango (Mangifera indica L.) in YSR district, Andhra Pradesh using remote sensing and geographic information system” was undertaken to identify the soil related constraints and delineate the spatial variability of soil fertility status in order to suggest fertilizer recommendation in YSR district of Andhra Pradesh using remote sensing and GIS techniques. Georeferenced samples (250 Nos) were collected from the study area following spatially balanced sampling technique. The soil samples were analyzed for physical properties like texture, colour, bulk density, particle density, percent pore space and water holding capacity, physico-chemical properties viz., pH, EC, OC, CEC, and free CaCO3 and chemical properties viz., available N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu. Similarly, leaf samples were analyzed for total N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu and fruit samples were analyzed for per cent juice, juice pH, TSS and vitamin-C. In irrigation water, quality parameters such as pH, EC, cations viz., Na+ , Ca2+, Mg2+, K+ and anions viz., CO3 2- , HCO3 - , Cl- , SO4 2- , RSC and SAR were analyzed. Sixteen pedons were selected based on the total area of mango grown in each mandal and were studied for soil properties to know constraints in sub surface layers of soils. xvi The various soil textural classes identified in surface soils were 42.80 per cent was sandy loam, 38.00 per cent was sandy clay loam, 12.40 per cent was loamy sand, 4.4 per cent was sandy clay and 2.40 per cent was clay loam. Texture of surface horizons and sub-surface horizons in pedons varied from sandy loam to sandy clay loam and gravel nature was seen in subsurface layers of some of the mandals. The colour of the soils in the study area had their Munsell colour notation in the hue of 10 YR / 7.5 YR / 5 YR / 2.5 YR with value of 3 to 6 and chroma of 2 to 8. The colour in all pedons varied from very dark red to dark greyish brown with a hue ranged from 2.5 YR to 10 YR, value ranged from 3 to 6 and chroma varied between 1 and 8. The pH of the study area was neutral to moderately alkaline in reaction. Out of total study area 38.80 per cent was neutral, 41.20 per cent was weakly alkaline, 19.20 per cent was moderately alkaline and 0.80 per cent was strongly alkaline in soil reaction. All the pedons of the study area were neutral to moderately alkaline in reaction. The orchard soils were non-saline in nature as the EC of these soils was far below 1.0 dS m-1 . The study area soils were low to medium in organic carbon at surface and low in sub-surface layers. The organic carbon content decreased with increasing depth. Out of all the surface soils of mango orchards studied, 80.00 per cent were low in available N and 20.00 per cent were medium in available N, 5.60 per cent were low in available P, 92.00 per cent were medium in P and 2.40 per cent were high in P. However, about 32.00 per cent were low in available K, 35.20 per cent were in medium range and 32.80 per cent were in high range. The higher exchangeable calcium and magnesium status was observed in all the orchards. In pedons the available nitrogen was ranged from 59.79 to 273.12 kg ha-1 and were low in available nitrogen. The available nitrogen was significantly and positively correlated (r = +0.514**) with organic carbon. The available phosphorus varied from 5.05 to 45.05 kg ha-1 . All the pedons showed a decreasing trend with depth. The available potassium in different pedons ranged from 49.98 to 512.05 kg ha-1 soil. The lowest value of 49.98 kg ha-1 was observed in pedon 10 and the highest was 512.05 kg ha-1 . Calcium, magnesium and sulphur contents recorded sufficient in all the villages of twelve mandals. All pedons showed an increasing trend with depth for exchangeable calcium and magnesium whereas deceasing trend with available sulphur and available micronutrients. The data on micronutrient status in these twelve mandals of the study area revealed that copper and manganese content in almost all soils was sufficient whereas iron (50%) and zinc content (48%) was deficient in the soils of Veeraballi and T. Sundupalle mandals. Two per cent of the leaf samples were deficient in N, 8 per cent deficient in P and 4 per cent deficit in K. N, P, K, Ca and Mg were 42, 12, 14, 2 and 12 per cent low in leaf samples, respectively while N, P, K, Ca and Mg were 4, 50, 16, 18 and 18 per cent were high in leaf samples, respectively. Zn deficiency in xvii leaf was the most severe among the 10 mineral elements tested and 90 per cent of samples were deficient in Zn, followed by Fe (64%), Mn (36%) and Cu (25%). However, the average leaf content of N, P, Ca and Cu was 1.27, 0.12, 2.39 and 8.9 per cent, respectively, which was within the optimum range. The correlation between fruit yield, soil pH and CaCO3 in soil was found to be negative and significant whereas the correlation between fruit yield and soil EC was found to be negative and non-significant Fruit yield was positively and significantly influenced by soil organic carbon content (r = 0.360), because the organic carbon content of the soil had a significant positive influence on soil N (r = 0.716**). The soil mineral nutrients like N, P and K influenced the fruit weight significantly and positively (r = 0.469*, r = 0.446* and r = 0.415*, respectively). Fruit juice per cent had significant and positive relation with soil N (r = 0.353*) and P (r = 0.364*). Soil P had a significant and positive correlation with TSS (r = 0.438*). The pH of the irrigation water samples collected from mango orchards of study area varied from neutral (6.77) to mildly alkaline (8.05). The EC of the irrigation water varied from 0.82 - 3.87 dS m-1 with a mean value of 1.82 dS m-1 . According to the irrigation water EC classification, 76 per cent of the water samples were high in salinity with C3 class and 24 per cent of the water samples were categorized with high salinity (C4 class). The concentration of major anions of irrigation water collected from all the mango orchards were in the order of HCO3 - > Cl- > SO4 2- > CO3 2- and the cations were in the order of Na+ > Mg2+ > Ca2+ > K+ . The general constraints that were observed in the soils of mango orchards were low organic carbon, low to medium available nitrogen and phosphorus, wide spread deficiency of zinc and iron, low to medium Mn, wide occurrence of soil alkalinity, calcareousness and poor quality of irrigation water i.e., high to very high salinity of the irrigation water. Soil nutrients thematic maps were prepared using remote sensing and GIS techniques and delineated the soil related constraints. On the basis of fertility mapping, suitable recommendations were made in the study area in terms of available nutrients. In conclusion, it can be summarized that the new technologies such as remote sensing, GIS and GPS have opened a new era in generating natural resource database to integrate and assess their potential on spatial basis. Integration of GIS in the present study was highly useful in identification of soil related constraints spatially and in generating the fertilizer recommendation maps and soil suitability assessment. Also, by identifying the soil related constraints in the study area, it made clear that there is a need of adoption of soil test crop response based integrated plant nutrition system (STCR-IPNS) and micronutrient recommendations to mango would enhance the crop productivity, fertilizer use efficiency and alleviate the deficiencies over long run
Description
Keywords
Citation
Collections