MECHANICAL MEASURES OF SOIL CONSERVATION.pptx

The mechanical measures of soil conservation include various engineering techniques and structures which are adopted to supplement the biological methods when the latter alone are not sufficiently effective. These are also called as engineering measures.

1. WELCOME

2. MECHANICAL MEASURES OF SOIL CONSERVATION Presented by: Venkata sri Akshay Duddumpudi BAD-2021-03 PhD Scholar, Department of Agronomy Agricultural College, Bapatla Acharya N G Ranga Agricultural University ACHARYA N G RANGA AGRICULTURAL UNIVERSITY Agricultural college, Bapatla . DEPARTMENT OF AGRONOMY AGRON -606 Presented to: Dr. b. venkateswarlu Professor & Head, Department of Agronomy Agricultural College, Bapatla Acharya N G Ranga Agricultural University

3. Flow of Presentation

4. Mechanical measures of soil conservation The mechanical measures of soil conservation include various engineering techniques and structures which are adopted to supplement the biological methods when the latter alone are not sufficiently effective. These are also called as engineering measures. These practices aim at the following objectives: 1. To reduce the velocity of run-off water and to retain it for long period so as to allow maximum water to be absorbed and held in the soil. 2. To divide a long slope into several small parts so as to reduce the velocity of run-off water to the minimum, and 3. Protection against erosion by wind and water.

5. Different Mechanical/Engineering Measures BBF Contour bunding Graded bunding Contour trenches Contour stone wall Compartmental bunding Random tied ridging Basin listing Bench terracing Micro catchment Farm ponds Percolation ponds Check dams

6. Based on the slope, some important conservation practices Conservation practice Slope Contour bunding Upto 6% Graded bunding 6-10% Graded trenches 10-16% Bench terracing 16-33%

7. Broad Beds and Furrows (BBF) In a broadbed -and-furrow system, runoff water is diverted into field furrows (30 cm wide and 30 cm deep). The field furrows are blocked at the lower end. When one furrow is full, the water backs up into the head furrow and flows into the next field furrow. Between the field furrows are broad beds about 170 cm wide, where crops are grown.

8. It is suitable when the slope of the land is < 3% The broad bed and furrow system is laid within the field boundaries. The land levels taken and it is laid using either animal drawn or tractor drawn ridgers . Functions Conserves soil moisture in dryland Controls soil erosion. Acts as a drainage channel during heavy rainy days. General information

9. Broad Beds and Furrows (BBF) (Source: tnauagritech )

10. Contour Bunding Function To intercept the runoff flowing down the slope by an embankment. It helps to control runoff velocity. Salient features It can be adopted in light and medium textured soils. It can be laid upto 6% slopes. It helps to retain moisture in the field.

11. SPECIFICATION FOR BUND CROSS SECTION Depth of soil (m) Base width (m) Top width (m) Height (m) Side slope (m) Area cross section ( sq.m ) Shallow soils ( 7.5 – 22.5 cm) 2.67 0.38 0.75 1.5 : 1 1.14 Medium soil ( 22.5 – 45 cm) 3.12 0.60 0.85 1.5 : 1 1.56 Medium deep soils 4.25 0.60 0.90 1.5 : 1 2.18

12. Bunding options Soil type Rainfall (mm) Contour bund Light soil <600 Graded bund All soils <600 Bench terraces Deep soil >1000 Graded border strip Deep Alfisol and related red soil >800

13. Soil Type Rainfall In-Situ Moisture Conservation Techniques Red soil Low Dead furrow at 3-6 m interval   Medium Sowing on flat bed and riding later with eventual cultivation   High Graded border strips Black soil Low Contour cultivation   Medium Dead furrows at 3-6 m interval   High Graded open furrow (0.2 to 0.3 m 3 ) at 10 m interval across the slope

14. Contour bunding (Source: Prepmate ) (Source: tnauagritech )

15. Graded bunding In situations where the rain water is not readily absorbed either de to high rainfall or low intake in soil, graded bunding is recommended. Spaced at the same interval as contour bunds. The cross-section and grade of channel are designed for conveying the peak rate of inter- bunded runoff at non-scouring and siting velocity.

16. Graded bunding

17. Contour trenches and staggered trenches It was suitable where slope of the land is > 33.33% Dimension of trenches- 2 x 1 x 1 m3 Trenches are excavated in contours and excavated soil was used to form bunds in the down line. The trenches were formed in 5 to 10 feet vertical distance. It helps to reduce velocity of water. It checks soil erosion.

18. Contour trenches (Source: RAO)

19. Contour stone wall Contour stone wall is constructed where the slope is > 15 to < 30% under the guidance of engineers . In case of highly hill areas, contour trenches were constructed along with stone wall. It is suitable for shallow and gravel soil. It is recommended where difficult to construct bench terrace. It helps in land preparation and checks soil erosion. Note : If the length of the contour stone wall is more than 800 feet, the excess water flow could be guided through contours with proper outlets.

20. Contour stone wall (Source: tnauagritech ) (Source: Roy & Indranil,2009)

21. Compartmental bunding Compartmental bunding means the entire field is divided into small compartments with pre determined size to retain the rain water where it falls and arrest soil erosion. The compartmental bunds are formed using bund former. The size of the bunds depends upon slope of the land. Compartmental bunds provide more opportunity time for water to infiltrate into the soil and help in conserving soil moisture.

22. Salient features : Compartmental bunding is an effective moisture conservation measure in dryland . It is suitable for lesser rrainfall areas and the slope is < 1% The lands are divided into small compartments with the dimension of 8 x 5 m 2 . Small compartments act as a dam and store the rainfall received in the compartments for longer period. It increases water holding capacity of the soil. It can be formed while ploughing itself or before early sowing. Reduces the formation of cracks. It will overcome the disadvantages of contour bunding .

23. Compartmental bunding (Source: Patil et al., 2015)

24. Random Tied ridging The ridges are vertically tied at shorter interval to create rectangular water harvesting structures. During heavy rainy season it facilitates to infiltrate water to the soil. The slight sloppiness in the tied ridges facilitates draining of excess water infiltrate into the soil. Summer ploughing , broad bed and furrows, ridges and furrows, random tie ridging, compartmental . bunding etc. are the various in situ water harvesting methods for black and red soils cause an increase of up to 15 per cent in crop yields. It conserves soil and moisture in redsoils .

25. Tied ridging (Source: Panyan et al., 2015)

26. Basin listing In this method of soil and water conservation basins are constructed using a special implement called basin- lister . These basins are constructed across the slope. Basin listing provides maximum time to rain water for infiltration into the soil. Bench terracing On steeply sloping lands, the slopes where such terraces are found useful vary from 16 to 33 per cent. Bench terraces with 100 m length, longitudinal grades in the range of 0.2 to 0.8 per cent are recommended for Alfisols of high rainfall regions.

27. Bench terraces are suitable where soil depth is more than 21/2 feet and it can be laid in slopy land ranges from 16.67 to 33%. In highly slopy lands (8-15%) three types of bench terraces are planned viz., horizontal, inward and outward based on soil type and water holding capacity. In hilly areas, cultivation of horticultural crops under bench terracing method conserve soil, moisture and reduces nutrient loss and increases the yield. It also reduces soil erosion. Note: If the length of the Bench Terraces is more than 400 feet, the excess water flow could be guided through contours with proper outlets.

28. Basin listing (Source: Arizona memory project) (Source: Library of congress)

29. Bench terracing (Source: FAO) (Source: tnauagritech )

30. Micro Catchment In drylands , quantum of rainfall is not sufficient for the cultivation of crops , if tree cultivation is possible means developing micro catchments around the tree will improve the storage of rainfall and increase the yield. In slopy land this type of catchments could be developed across the slope. For tree crops, according to inter space available catchments are formed. It stores rain water where it falls and helps in growth of trees. For plain and hill areas the shape of the bunds were decided. Micro catchments size of 5 x 5 m and the quantum of rainfall is 20 mm will give 500 liters of water.

31. Circular and semicircular basins It is suitable for fruit crops. Bundings were for formed individually for each tree. Circular bunding recommended for plain land area, whereas sloppy lands with semicircular or crescent bunding . Distance between bunding depends upon tree spacing 'V' ditches In the land areas at 4 to 6 m intervals V shaped ditches are formed with the help of machine or animal drawn machine. Down the line of ditches covered with soil bunding and the trees are planted in the pits based on the spacing needed. Catch pits

32. Micro catchments (Source: Das&Bandhopadhay , 2013) (Source: FAO)

33. Farm ponds Farm ponds are small water bodies formed either by the construction of a small dam or embankment across a waterway or by excavating or dug out. The water is usually harvested from a small catchment area and then used for irrigation during prolonged periods Specifications: In the selected farm land the farm pond dimension of 8m x 8m x 1.5m can be constructed for the every 1 or 2 ha of land area.

34. Water spreading area ( sq.m ) Depth of water (m) Suitable uses 2000 to 10000 2.5 - 3.0 Irrigation, fisheries and drinking water 2000 to < 10000 1.5 – 2.5 Irrigation & drinking water < 2000 1.5-2.5 Pot irrigation for trees and drinking water Benefits of farm ponds : It collects excess runoff during rainy period. Stored water can be used for supplemental irrigation to crops. It is useful as drinking water for cattles during drought situation. It can be used for spraying pesticides. It conserves soil and moisture.

35. 1 Bottom Area 20 m x 20 m 2 Top Area 35 m X 35 m 3 Depth 2.2 m 4 Cost of lining material (Rs) 85,000 5 Excavation (Rs) 20,000 6 Coir dust & spreading (Rs) 2,000 7 Spreading plastic lining and sheet welding (Rs) and with earth cover 27,000 8 Cost of inlet and outlet structures 66,000 9  Total cost (Rs)  2,00,000

36. Farm pond Source: Krishijagran ) (Source: tnauagritech )

37. Percolation ponds Percolation ponds are small ponds located mostly in low lying areas of public lands and formed in order to store the run-off of rainwater and to allow it to percolate downwards and sideways. Deep ponds are preferred since evaporation of the stored water therein will be less. It has been observed that the percolation ponds are effective up to a distance of 1000 metres on the downstream side and wells within this range are benefited with more replenishment of water.

38. Benefits : It replenish ground water during rainy season . It reduces velocity of water thereby reduce soil erosion. Reduces siltation in water tank, ponds and check dams. Floods can be avoided. Generates employment during dry period. Increased cultivable area. Points to be considered. Area should't be hard and rocky. Capacity of the ponds depends upon amount and frequency of water flow. In the downstream there should be farm lands and irrigation well. The depth should be atleast 1.5 m. The depth should be atleast 1.5 m. Strengthen the bunds with soil .

39. Percolation pond (Gale, 2005)

40. Gully Control Measures Temporary Gully Control Structures (TGCS) • TGCS have a life span of 3 to 8 years and they are pretty effective where the amount of runoff is not too large. • These are made of locally available materials. • Basic purposes they serve are to retain more water as well as soil for proper plant growth and prevent channel erosion until sufficient vegetation is established on the upstream side of the gully.

41. TGCS are of many types: 1 . Woven wire check dams 2 . Brush dams 3 . Loose rock dams 4 . Plan or slab dams 5 . Log check dams 6 . Boulder check dams 7 . Gabion

42. Design Criteria of TGCS • The overall height of a temporary check shouldn’t ordinarily be more than 75 cm. An effective height of about 30 cm is usually considered sufficient. Also, sufficient freeboard is necessary. • Life of the check dams under ordinary conditions should be in between 3 to 8 years. • Spillway capacity of check dams is generally designed to handle peak runoff that may be expected once in 5 to 10 year return period. • Since the purpose of check dams in gully control is to eliminate grade in the channel, check dams theoretically should be spaced in such a way that the crest elevation of one will be same as the bottom elevation of the adjacent dam up-stream.

43. Woven Wire Check Dams • Woven-wire check dams are small barriers which are usually constructed to hold fine material in the gully. • Used in gullies of moderate slopes (not more than 10 percent) and small drainage areas that do not have flood flows which carry rocks and boulders. • Help in the establishment of vegetation for permanent control of erosion. • Dam is built in half-moon shape with the open end up-stream. • To construct a woven-wire dam, a row of posts is set along the curve of the proposed dam at about 1.2 m intervals and 60-90 cm deep.

44. • Heavy gauge woven wire is placed against the post with the lower part set in a trench (15- 20 cm deep), and 25-30 cm projected above the ground surface along the spillway width. • Rock, brush or sod may be placed approximately up to a length of 1.2 m to form the apron. • For sealing the structure, straw, fine brush or similar material should be placed against the wire on the upstream side upto the height of spillway.

45. Woven wire check dams (Source: Agr . Handbook No. 61. USDA, SCS).

46. Woven wire check dams

47. Brush Dams • Cheap and easy to build, but least stable of all types of check dams. • Best suited for gullies with small drainage area. • Centre of the dam is kept lower than the ends to allow water to flow over the dam rather than around it. • For a distance of 3 to 4.5 m along the site of the structure, sides and bottom of the gully are covered with thin layer of straw or similar fine mulch. • Brushes are then packed closely together over the mulch to about one half of the proposed height of dam.

48. • Heavy galvanized wire is used to fasten the stakes in a row, as well as to firmly compress the brushes in places. • Sometimes large stones are also placed on top of brush to keep it compressed and in close contact with the bottom of the gully. • Major weakness is the difficulty of preventing the leaks and constant attention is required to plug openings of appropriate size with straw as they develop.

49. Brush dam (Source: Agr . Handbook No. 61. USDA, SCS).

50. Brush dam

51. Loose Rock Dams • Loose rock dams made of relatively small rocks are placed across the gully. The main objectives for these dams are to control channel erosion along the gully bed, and to stop waterfall erosion by stabilizing gully heads. • Loose stone check dams are used to stabilize the small gullies. • The length of the gully channel is not more than 100 m and the gully catchment area is 2 ha or less. • These dams can be used in all regions. • Used in areas where stones or rocks of appreciable size and suitable quality are available.

52. • Flat stones are the best choice for dam making. • Stones can be laid in such a way that the entire structure is keyed together. • A trench is made across the gully to a depth of about 30 cm. This forms the base of the dam on which the stones are laid in rows and are brought to the required height. • The centre of the dam is kept lower than the sides to form spillway. • To serve as an apron, several large flat rocks may be countersunk below the spillway, extending about 1 m down-stream from the base of the dam.

53. Loose Rock Dams (Source: Agr . Handbook No. 61. USDA, SCS).

54. Loose Rock Dams

55. Log Check Dam • They are similar to plank or slab dams. Logs and posts used for the construction are placed across the gully. • They can also be built of planks, heavy boards, slabs, poles or old railroad ties. • The main objectives of log check dams are to hold fine and coarse material carried by flowing water in the gully, and to stabilize gully heads. • They are used to stabilize incipient, small and branch gullies generally not longer than 100 m and with catchment areas of less than 2 hectares. • The maximum height of the dam is 1.5 m from the ground level. Both, its downstream and upstream face inclination are 25 percent backwards.

56. Log Check Dam

57. Log Check Dam

58. Boulder Check Dams • Boulder check dams placed across the gully are used mainly to control channel erosion and to stabilize gully heads. • In a gully system or multiple-gully system all the main gully channels of continuous gullies (each continuous gully has a catchment area of 20 ha or less and its length is about 900 m) can be stabilized by boulder check dams. • These dams can be used in all regions. • The maximum total height of the dam is 2 m. Foundation depth must be at least half of the effective height.

59. • The thickness of the dam at spillway level is 0.7 to 1.0 m (average 0.85 m), and the inclination of its downstream face is 30 percent. • The upstream face of the dam is usually vertical. If the above-mentioned dimensions are used, it is not necessary to test the stability of the dam against overturning, collapsing and sliding. • The dimensions of the spillway should be computed according to the maximum discharge of the gully catchment area. • The form of the spillway is generally trapezoidal.

60. Boulder Check Dams

61. Boulder Check Dams

62. Sandbag Check-Dam • Sandbag check-dams are made from used jute or polyethylene bags (50 kg) filled with soil/sand. • The bags are piled up to a maximum of 3 – 4 layers to form a small check-dam. • This cheap technique is particularly useful in areas with insufficient supply of stones for building ordinary check-dams. • By erecting sandbag dams large rills or small gullies (finger gullies) can be controlled, while they are not suitable for the treatment of large gullies.

63. Sandbag Check-Dam

64. Gabion Check Dam • If the catchment area of a gully is 20 ha or less and the length of the gully is about 1 000 m, channel erosion will be controlled by boulder check dams, but the first check dam and its counter-dam should be constructed as gabions. • If the gully crosses a road, gabion check dams may be built above and below the road at the junction points. • In addition, gabion check dams combined with gabion retaining walls can be used to stabilize landslides in the upper portions of the gully. • Generally, it is neither necessary, nor economical to build a series of gabion check dams to control channel erosion along the gully beds.

65. Gabion Check Dam

66. Permanent Gully Control Structures (PGCS) • If the erosion control programmer requires bigger structure, then PGCS are used. • PGCS, built of masonry, reinforced concrete or earth are efficient supplemental control measures in soil and water conservation. • They are helpful in situation where vegetative measures or temporary structures fail to serve the purpose of controlling the concentration of runoff or reclaim a gully. • PGCS are generally used in medium to large gullies with medium to large drainage area. • PGCS are designed to handle runoff from the heaviest rains that may be expected once in 25 to 50 years or more depending upon the estimated life of the structure.

67. Basic permanent structures, generally employed in stabilizing gullies are: ➢ Drop spillway ➢ Drop-inlet spillway ➢ Chute spillway ➢ Permanent earthen check dams

68. Basic Components of PGCS These components can be divided into three groups: 1 . Inlet: Water enters the structures through the inlet, which may be in the form of a box or weir in a wall. 2 . Conduit: The conduit receives the water from the inlet and conducts it through the structure. It restricts the water to a definite channel. The conduit may be closed in the form of a box channel or it may be open as in a rectangular channel. 3 . Outlet: Its function is to discharge the water into the channel below at a safe velocity. The outlet should provide for the dissipation of kinetic energy of the discharge within the confines of the structure.

69. Drop Spillway • It is a weir structure, in which flow passes through the weir opening, fall or drops on an approximately level apron or stilling basic and then passes into the downstream channel. • Its use is limited to a maximum drop of 3 m. • It is mainly used at the gully bed to create a control point. • Several such drop structures are constructed across the gully width throughout the length at fixed intervals. • The series of such structures, develop a continuous break to flow of water, causing deposition of sediments and thus filling the gully section. • Sometimes, the drop structures are also used at the gully head to pass the flow safely and controlling the gully head.

70. Drop Spillway

71. Drop Spillway

72. Drop Inlet Spillway • A drop inlet or shaft spillway is one in which the water enters through a horizontally positioned circular or rectangular box type riser or inlet and flows to some type of outlet protection through a circular (horizontal or near horizontal) conduit. • The drop inlet spillway is ideally suited to conditions when there is need to control the downstream channel flow by providing a temporary storage upstream of the structure. • It consists of an earthen dam and a pipe spillway. • The dam provides the temporary storage of runoff from the contributing watershed while the spillway permits the design discharge to pass downstream. • It is adapted where drop is > 3.0 m.

73. Drop Inlet Spillway

74. Drop Inlet Spillway

75. Chute Spillway • Chute (open channel or trough) spillway is a spillway whose discharge is conveyed from the upper reach of the channel or a reservoir to the downstream channel level through an open channel placed along a dam, abutment (supporting wall), or through a saddle. • Chute structures are useful for gully head control and they could be used for drops upto 5 to 6 m. • Chute spillways are constructed at the gully head to convey the discharge from upstream area of gully into the gully through a concrete or masonry open channel, when drop height exceeds the economic limit of drop structures. • Chute spillway has more advantage than a drop spillway, when a large runoff volume is required to be discharged from the area. • Flow in a chute spillway is at super-critical velocities.

76. Chute Spillway

77. Chute Spillway

78. Earthen Dam • An earthen embankment is a raised confining structure made from compacted soil. • The purpose of an earthen embankment is to confine and divert the storm water runoff. • It can also be used for increasing infiltration, detention and retention facilities. • Earthen embankments are generally trapezoidal in shape and most simple and economic in nature. • They are mainly built with clay, sand and gravel, hence they are also known as earth fill dams or earthen dams. • They are constructed where the foundation or the underlying material or rocks are weak to support the masonry dam or where the suitable competent rocks are at greater depth. • They are relatively smaller in height and broader at the base.

79. Earthen Dam (Source: Michael and Ojha , 2012)

80. Research Findings

81. Table 1. Yield of Cotton and Millet in farm fields treated with and without Contour bunding Technique Crop species Cotton (kg ha -1 ) Millet grain (kg ha -1 ) Contour bunding 1998 1322 No contour bunding 1617 * 890 ** * (p<0.05), ** (p<0.01) ( Traore et al., 2017) (Southern Mali)

82. Figure 1. Millet field in southern Mali without application of contour bunding (NCB) and with CB NCB CB ( Traore et al., 2017) (Southern Mali)

83. Table 2. Grain yield of crops in fields with and without Contour Bunding . Crop Yield (kg ha −1 ) and WP (kg mm −1 ) Bougouni district Koutiala district NCB WP CB WP NCB WP CB WP Sorghum 1292 2.11 1530* 2.50 1450 2.68 2120* 3.92 Maize 1360 2.22 2310** 3.78 1300 2.40 2020** 3.73 Millet 1370 2.24 2130** 3.48 1350 2.49 2720** 5.02 Groundnut 1180 1.93 1400* 2.29 1114 2.06 1920** 3.54 (WP refers to water productivity; CB refers to contour bunding ; NCB refers to no contour bunding .) *Statistically significant at P < 0.05, **Statistically significant at P < 0.01. ( Birhanu , et al. 2019) (Southern Mali)

84. Table 3. Runoff coefficient and soil loss in Bougouni and Koutiala districts during 2016 and 2017 cropping season Runoff coefficient (%) Soil loss kg ha −1 yr −1 Technique CB 19.25 b 4970 b No CB 35.62 a 13090 a P value 0.004 0.02 Site Koutiala 23.75 b 5733 b Bougouni 31.12 a 11,332 a P value 0.03 0.04 Year 2016 30.87 a 11,228 a 2017 24 b 5837 b P value 0.05 0.04 (Note: values with different letters are statistically different at P = 0.05. Column means represent runoff coefficient and soil loss; row values show technology, experimental site andyear of data record.) ( Birhanu , et al. 2019) (Southern Mali)

85. Table 4. Nutrient losses in eroded soil (kg ha −1 yr −1 ) under CB and non CB in Bougouni and Koutiala districts during 2016 and 2017 cropping season . Description C N P Ca Mg K Technique CB 45 b 5 b 4 b 5 b 3 b 4 b No CB 106 a 11 a 8 a 9 a 5 a 7 a P value 0.04 0.006 0.02 0.01 0.01 0.02 Site Koutiala 75 7 4 8 4 5 Bougouni 76 8 6 7 4 6 P value 0.97 0.98 0.06 0.6 0.62 0.76 Year 2016 112 a 10 a 7 a 10 a 5 a 7 a 2017 39 b 5 b 4 b 5 b 3 b 3 b P value 0.02 0.01 0.12 0.008 0.003 0.01 ( Birhanu , et al. 2019) (Southern Mali) (Note: values with different letters are statistically different at P = 0.05.)

86. Table 5. Month wise LAI and canopy interception for custard apple and atemoya during 2013-14. Plantation Month Leaf Area Index, LAI Canopy Interception, (mm)   CCT Treated catchment Non Treated catchment CCT Treated catchment Non Treated catchment   Custard apple June 0.26 0.22 0.01 0.01 July 0.27 0.23 0.01 0.01   August 0.55 0.49 0.03 0.02   September 0.69 0.63 0.03 0.03   October 0.70 0.62 0.04 0.03   November 0.66 0.57 0.03 0.03   December 0.50 0.43 0.03 0.02   January 0.38 0.31 0.02 0.02   February 0.08 0.06 0.00 0.00  

87. Plantation Month Leaf Area Index, LAI Canopy Interception, (mm) CCT Treated catchment Non Treated catchment CCT Treated catchment Non Treated catchment Atemoya June 0.42 0.37 0.02 0.02 July 0.57 0.47 0.03 0.02 August 1.40 1.21 0.07 0.06 September 1.91 1.61 0.10 0.08 October 1.86 1.33 0.09 0.07 November 1.81 1.35 0.09 0.07 December 1.28 1.09 0.06 0.05 January 1.08 0.83 0.05 0.04 February 0.71 0.64 0.04 0.03 March 0.39 0.11 0.02 0.01 ( Patode et al., 2015) (AICRPDA, Dr.PDKV , Akola)

88. Table 6: Crop growth and yield components of sunflower as influenced by rainwater conservation and integrated nutrient management practices at Research farm during 2008–09. Treatments Plant height (m) Head weight (g plant −1 ) Stover yield (kg ha −1 ) Grain yield (kg ha −1 ) Rainwater conservation practices Flat bed 130.7 36.28 1120 886 Compartmental Bunding 144.7 48.47 1299 1079 Ridges and Furrows 140.8 47.37 1298 1072 S.Em.± 1.8 1.77 110 30 LSD (p < 0.05) 5.6 5.58 ns 119 Integrated nutrient management INM1 135.8 42.01 1128 954 INM2 138.3 44.07 1208 1011 INM3 142.1 46.05 1379 1071 S.Em.± 1.3 1.04 76 44 LSD (p < 0.05) 3.7 3.00 234 136 ( Patil et al., 2015) (Research farm, Bellary)

89. Table 7. Sediment losses on runoff plots as influenced by soil conservation measures Conservation Measure Soil loss (t/ha) September - May November - May Control, none 3.81 a * 3.51 a Control, fertilizer 1.59 b 1.33 b Bench terraces 1.13 bc 0.68 bc Grass bunds 0.81 bc 0.40 c Grass + Gliricidia bunds & mulch 0.53 c 0.34 c *Values followed by different letters are significantly different (p < 0.05) using protected LSD analysis (Stephen and Jill, 1990) ( Kerinci , Sumatra)

90. Maharashtra has a rugged topography and basaltic geological formation so there is limitation on canal as well as well irrigation. There are many measures for the conservation of water and soil. They are performed by various government agencies. See the following table ( Table 8 )….. Objective Types of Measures Agency Water conservation Vanrai, Kaccha earthen, Bund, Nala Bandhara, Nala Plugs, check dam, Percolation tank Soil Conservation Department Soil Conservation Forestation, Continuous contour trench Forest Department & Social Forestry Contour trench, Contour bonding, Farm pond, Check dam Soil Conservation Department Strengthening of drinking water sources Fracture Seal Cementation, Jacket well, Stream blasting, Bore Blast Technique, Bore well flooding. Groundwater Surveys & Development Agency ( Nitin Bajirao , 2016) (Maharashtra)

91. Table.9 Yield and Growth parameters of Mango using Micro-catchments Treatments No. inflorescence /branch No of fruit set/ inflorescence Fruit yield (Kg/tree) T 1 -Half-moon 4.6 5.1 55.5 T 2 -Circle 3.9 4.0 50.3 T 3 -V-bund 4.4 4.6 53.0 T 4 -control 10.4 2.2 45.4 Cd 0.71 0.75 3.4 SEM 0.24 0.26 1.2 (Ali, 2017) ( Ramanagara , Karnataka)

92. Conclusion The purpose of mechanical soil conservation measures is to protect the soil from the impacts of heavy rain and wind and prevent soil erosion. Mechanical measures usually involve construction of mechanical barriers across the direction of flow of rain water to retard or retain runoff and thereby reduce soil and water loss. Different measures can be adopted based on the different conditions and have a very significant effect on the soil loss and yields.

93. THANK YOU