Studies at AFRI demonstrate a dramatic impact of micro-catchments rain water harvesting technology on tree growth, which improved by 4 to 5 folds on micro-catchments when compared with control in case of Azadirachta indica, Prosopis cineraria and Tecomella undulata. The structures - ring pits, big saucers and ridge and furrow have been found beneficial. Based on growth, cost benefit analysis, employment and social conditions trench and mound and saucers of 2.5 m diameter have been recommended. The water harvesting techniques as they prevent runoff losses (30-50 %) maintain higher soil moisture regime and facilitate better tree establishment and growth owing to better development of root system, improved water use efficiency, improved nutrient use efficiency (4-7 times), thus give a good start to young plantations. Demonstration of this technology was carried out in farmers's field (at Jasol, Barmer district), experimental field of AFRI, in community land (at Rohat in Pali district) and forest lands in Palanpur district, Gujarat and Nagaur in Rjasthan. The results were extended for other species like Dalbergia sissoo, Eucalyptus camaldulensis, Ziziphus mauritiana etc.
Moisture conservation practices such as mulching with local under shrub like Crotalaria burhia, soil tillage and intercultural operations in dry zones adequately demonstrate their utility in plantation establishment and early growth of trees by increasing plant height (24%) and collar circumference (27%) in Azadirachta indica. This impact is attributed to the prevention of evapo-transpiration losses and consequently high soil moisture regimes and moderation of thermal regimes (by 5 0C) in the vicinity of roots and consequently maintaining better microbial activities resulting in transformation and availability of nutrients. Study on partitioning of water loss in a lysimeter study indicated that water losses from the E. camaldulensis plot (irrigated at the rate of 36.2 mm per irrigation) was 4.75 mm day-1 (19 lit day-1) during summer as compared to 3.45 mm day-1 (13.8 lit day-1) in A. nilotica and 2.62 mm day-1 (10.56 lit day-1) in D. sissoo plot. Simple mulching with locally available Crotalaria burhia under shrub saved the water loss by 0.15 mm day-1.
Reactivation of sand drift and ripple formation is a common feature, where only tree species are planted. This situation could be very well tackled by introducing surface vegetations like Cassia angustifolia and locally available grass species for faster stabilization of sand dune and control of sand drift reactivation with additional benefits of biomass for fuel wood and fodder.
The benefits of introducing C. angustifolia over other species are its greenness during summer when maximum sand drifts take place and additional economic benefits a farmer can get by harvesting the leaves having medicinal value. Our observations near Bikaner showed that at the age of 50 months, A. tortilis produced 5.2 tones ha-1 fuel wood as compared to 7.00 tones ha-1 from P. juliflora and 7.15 tones ha-1 from Calligonum polygonoides. C. polygonoides produced highest fuel wood utilizing minimum amount of soil water. Introduction of surface vegetation like Cassia angustifolia (medicinal plant) and locally available grass like Cenchrus ciliaris (for fodder production) along with the tree/ shrub species was found more suitable in early and effective stabilization of dune. Cenchrus ciliaris produced green fodder of 1.22 tones ha-1 year-1 with A. tortilis, 1.58 tones ha-1 year-1 with P. juliflora and 2.23 tones ha-1 year-1 with C. polygonoides. Cassia angustifolia produced dry leaves of 0.76 tones ha-1 year-1 with A. tortilis, 0.96 tones ha-1 year-1 with P. juliflora and 1.39 tones ha-1 year-1 with C. polygonoides with market cost of Rs 9120, 11520 and 16720, respectively @ Rs 12 kg-1. A combination of C. polygonoides and C. angustifolia was found most suitable to control sand drift and economic benefits, whereas the combination of C. polygonoides with C. ciliaris was beneficial in greater biomass production in terms of fuel wood and fodder.
Traditional practice of mulching can now be replaced with liver micro-windbreak of Cassia angustifolia
With best combination of Calligonum polygonoides and C. angustifolia
Increasing urbanization and industrialization have led to problem of increased amount of effluent discharge, whereas the amount of fresh water is decreasing day by day. Both the type of water need to conserve and to safely and economically dispose of wastewater, make the use of municipal or industrial effluent in tree plantation is a very feasible option. To ensure environmental quality in suburban area and better use of sewage/effluent water some experiments were carried out at AFRI. Seedlings of Eucalyptus camaldulensis, Acacia nilotica and Dalbergia sissoo were irrigated daily depending on potential evapo-transpiration (PET) of the area @1/2PET; @ 1PET and @ 2PET. Application of municipal effluent at 1/2 PET and canal water at 1PET produced same biomass at the age of 2/3 years when water requirement of plant was less. Thus there is saving of half of the quantity of drinking water. At the age of 4 years E. camaldulensis produced dry biomass of 20.1, 15.5 and 9.7 kg plant-1 whereas A. nilotica produced 13.3, 10.5 and 7.9 kg plant-1 and D. sissoo produced 14.8, 10.5 and 9.1 kg plant-1 by irrigating seedlings at the rate of 2 PET, 1 PET and 1/2 PET, respectively. In later years, irrigating plants @ 2PET had no significant influence on the growth over the rate 1PET, whereas there was reduced growth at 1/2 PET rate. Hence irrigation of these plants is recommended at 1 PET.
In another experiment, steel effluent generated metal toxicity, due to reduced soil pH and accumulation of metals in both soil and different seedling parts. Low soil pH enhance metal mobility, their uptake and the competitive effect of metal ions reducing absorption and translocation of Ca, Mg, K, N and P in plant parts altering physiological functions and ultimately lead to the seedling mortality. Addition of municipal and textile effluent to the steel effluent alleviated the toxicity level and increased the seedling survival period of seedlings by 1to2 months. Pure textile effluent affected the root and leaf growth adversely, because of Na induced Mg and micronutrients deficiency. Addition of municipal effluent to textile effluent enhanced the mineral status, physiological function, growth and biomass of the seedlings of Acacia nilotica, Dalbergia sissoo and Eucalyptus camaldulensis and recommended as one of the management strategies for utilization of textile industrial effluent in tree growing. Steel effluent needs further amelioration through raising pH and reduction in metal concentration before its disposal. Seedlings irrigated with municipal effluent showed maximum growth and plant nutrient concentration and suggested as better strategy to utilize it in raising woodlot to supply fuel wood in the vicinity of the suburban area.
Effluent discharge from city/industrial areas and its utilization in growing woodlot of Eucalyptus camaldulensis, Acacia nilotica and Dalbergia sissoo
Studies carried out at AFRI on species suitability, tree density and crop sequences while growing in tree -crop combination included tree species of Prosopis cineraria, Tecomella undulata, Emblica officinalis, Hardwickia binata and Colophospermum mopane. Agricultural/ medicinal crops tested were Vigna radiata, Pennesetum glaucum, Sesamum indicum, Cymopsis tetragonoloba, Vigna aconitifolia and Cassia angustifolia. P. cineraria was the best species for the agroforestry and was found less competitive than T. undulata for agricultural production. Prosopis cineraria produced utilizable biomass of 21-32 tones ha-1, whereas Tecomella undulata produced 17-30 tones ha-1 at 8 year of age and at a spacing of 4 x 3 m. Fruit yield of P. cineraria ranged from 350 -1040 g tree-1 at the age of 7 to 8 year. In another experiment P. cineraria provided utilizable biomass of 19.96 tones ha-1 including leaf fodder of 0.85 tones ha-1 at 12 year age and 208 tree ha-1 tree density. Crop yield was 7-15% less under T. undulta than under P. cineraria. However, it can be compensated by timber value, if a farmer wants to integrate T. undulata than P. cineraria in the agriculture field. However, yield reduced when agricultural crop was integrated at high density even for P. cineraria, thus concept of optimum density prevailed and the optimum density of P. cineraria and T. undulata observed by us was 833 at 2-3 years, 417 at 4-6 years, 278 at 7-8 years and 208 trees ha-1 at 9-11 years of tree age. Thus P. cineraria and T. undulata could be grown at 208 tree ha-1 up to 12 years without any significant reduction in agricultural yield and outputs from the trees are the additional benefits. The findings on Colophospermum mopane we observed that this tree species is more suitable for rehabilitation of degraded lands as compared to its integration in agricultural land under agroforestry.
Disturbances to the natural habitats through overgrazing, vegetation removal and mining is a common feature in most of the hilly areas like Aravallis, which is an ancient mountain and one of the oldest geological formations in the world and the home of many tribes of India, leading biological invasion and land degradation i.e., desertification. To restore these degraded hills an experiment was conducted by applying rainwater harvesting (RWH) and afforestation with different tree species (Ziziphus mauritiana, Acacia catechu, Azadirachta indica, Emblica officinalis, Dendrocalamus strictus, Gmelina arborea, Holoptelia integrifolia and Syzigium cumini). RWH structures (Contour trench [CT], gradonie [GD], box trench [BT], V-ditch [VD] and a control) and slope gradient (<10%, 10-20% and >20%) of plots were two levels of treatments. Application on RWH improved soil characteristics like reduction in soil pH and EC, and increase in soil organic carbon, NO3-N and PO4-P and reduced the gradients in soil water and nutrients between the plots of <10% slope and >20% slope. This not only reduced run-off water, soil and nutrient losses and enhanced the growth of the planted seedlings but also increased herbaceous layer productivity by 24 to 62% (average of six years) and soil carbon stock (by 3.8-fold). Contour trench and Box trench were beneficial in plant growth, whereas gradonie and V-ditch treatments were best for herbaceous growth and productivity. The impact of this practice was an increase in number of species from 39 in 2005 to 92 in 2009, increased water availability period from November to January/ March, fuel wood supply and fodder availability that resulted in enhanced socioeconomic condition of the tribal people residing nearby areas. Thus RWH and afforestation facilitates restoration process in degraded hills by improving soil nutrients, reducing resource gradient between slopes and enhancing plant growth and herbage biomass.
Tendency to over irrigate and seepage from the canal often cause water logging and salinity problems in most of the major irrigation projects. Engineering solution such as; ground water pumping and an extensive drainage system is required for prevention and remediation of this situation. In this context, Lysimeter based an experiment of controlled conditions was carried out at AFRI to observe the bio-drainage potential of selected species like; Acacia nilotica, Tamarix aphylla and Eucalyptus camaldulensis maintained at different water table i.e., adequate surface watering, 0.50-0.75 m and 1.00-1.25 m and salinity level i.e., canal water, saline water at 12 dSm-1 and saline water at 24 dSm-1. It was observed that rooting depth was restricted to the depth of water logging. Under water logging at 50 cm soil depth with normal water, E. camaldulensis, T. aphylla and A. nilotica used 64, 55.6 and 30.3 litres water per day. In E. camaldulensis and T. aphylla increase in water use has been observed with increase in water logging at non saline condition. However, in A. nilotica water use increased up to 12 dSm-1 and reduced drastically at 24 dSm-1. Under non saline condition, highest water of 73.6 L per day was recorded in A. nilotica at 12 dSm-1 treatment. With increase in salinity level, a decrease in daily water use was observed, which was greatest in E. camaldulensis (66%). T. Aphylla and A. nilotica recorded 57% and 51% decrease in water use, respectively. Native species showed higher tolerance towards salinity compared to E. camaldulensis. However, under water logging condition at shallow depth, E. camaldulensis outperformed A. nilotica and T. aphylla.
Increase vegetation cover and productivity of a waterlogged area in Indira Gandhi Nahar Pariyojana (IGNP), Jaisalmer studied were conducted, where Eucalyptus camaldulensis, E. fastigata, E. rudis and Corymbia tessellaris were planted on raised bunds, improved vegetation cover with simultaneous decrease in water table. Performance of E. rudis was best with respect to growth, biomass, transpiration rate and overall bio-drainage potential. E. rudis maintained uniform transpiration and photosynthesis rate throughout the year. Ground water level receded by 145 cm in E. rudis plot compared to 90 cm, 70 cm and 60 cm in C. tessellaris, E. camaldulensis and E. fastigata respectively. E. rudis showed high potential and be used as an efficient bio-drainage species for reclaiming waterlogged areas. Apart from the planted species, regeneration of Prosopis juliflora, Tamarix dioca and Saccharum munja in the area with recession of ground water table suggests effective reclamation of water logged area. These results can be utilized for rehabilitation of water logged area. Results of these studies demonstrated at various training programmes & workshops.
Lysimeter plantation maintained at different water table and salinity level
Capparis decidua (Forsk.) Edgew. is a multipurpose woody small size tree growing wild in arid regions and by grazing appear like large size bush. C. deciduas is an multipurpose plant species valued for its fruit used as vegetable and pickles, timber termite resistant and used in agricultural instruments. This is one of the major species of desert, which is drought hardy tolerate high temperature and has wide adaptation. The population is declining at an alarming rate due to overexploitation and damage to its habitat. Natural regeneration is through seeds, but the hostile environmental conditions of arid region limits the establishment of new seedlings. Its natural regeneration may also be affected due to peculiar seed characteristics, which are short-lived as well as dormant. Under laboratory conditions, the seeds exhibited poor germination leading to know possible causes and to develop suitable treatment to enhance germination. Ripe fruits of C. decidua were collected from Jodhpur and seeds were extracted by depulping. Seeds were dried at room temperature under fan for 48 hrs, before following study was initiated.
Seed germination in Capparis decidua (Forsk.) Edgew
The seeds of C. decidua were given various treatments; scarified by nicking at the cotyledonary end, chilling treatments, moistened seeds rolled in wet towel paper were kept at 3-5oC for two weeks, soaking in sulphuric acid (99.8%) for three minutes, paper lined in glass pertidishes moistened with different concentrations of GA3. All the treatments included four replicates of 50 seeds each. Germination was counted daily till 21 days and a seed was considered germinated when radicle attained at least 0.5 cm length.
In control the seeds exhibited only 1 % germination. The germination was increased to 39.5 % in seeds scarified by nicking. While seeds scarified with sulphuric acid showed only 10.5% germination. The seeds treated with GA3 (200 ppm) enhanced germination to 26.5% but showed significant increase in seeds scarified by nicking prior to treatment. The scarified seeds treated with 50 and 100ppm GA3 showed gradual increase in germination (49.5 and 52% respectively), but remained at par with the scarified seeds. At 200 ppm of GA3 the germination increased significantly to 74.5%. Higher concentrations of 400, 700, and 1000 ppm not only failed to increase germination but also significantly declined it, though all three remained at par with each other. Protocol developed for seed processing, pre-treatment and germination will be highly useful for SFDs and farmers for raising planting material of C. deciduas for afforestation and plantations respectively.
Process developed for post harvest treatment and enhancement of germination of seed of Commiphora wightii Arn. Bhandari (Guggal)
Commiphora wightii (Arn.) Bhandari commonly known as guggul is an important medicinal plants of arid region, produce oleo-gum resin which is highly valued for Ayurvedic and Allopathic medicines. This is over-exploited species due to distractive method of tapping for oleo-gum resin and species is considered endangered (IUCN and red data book) National regeneration is poor and artificial germination is also poor. The percentage of germination varied from 1 to 4% at Guggal Herbal Farm, Mangaliawas. Experiments were conducted to find reasons for low germinability/viability of guggal seeds and find out solution.
The fruit setting in guggal plants commenced from August to October and fruits start maturing in the month of November to December in almost entire guggal growing areas in Rajasthan. The fruit starts turning red from green is the indication of maturity indices in guggal and full mature and ripe fruit is red in colour. This is the right time for seed collection. However, due to red colour, birds eat fruits, when it is ripe and ready for harvest. Generally, half mature fruits were collected for seeds, this result into low germination.
To overcome this problem, developed fasten process of fruit ripening in guggal.
Half ripe-fruits of guggal were collected in the month of November 2006 from naturally growing trees. Fruits were brought to the laboratory and sealed in 200-micrown thick polythene bag and kept in the lab for 18-24h. All fruits were turned red. Then fruits were depulped and almost 80% seeds were of black colour and showed viability. Application of this technique has enhanced seed germination and ease in seed collection for guggal propagation.
Seeds of guggal showed two type of colour viz; 50-70% white colour and remaining seeds appeared blackish in colour. Black coloured seeds showed 80-90 percent germination and they are viable. However, removal from seedlot, by picking, is time and labour intensive process. For this used a technique known as floater method and seedlot containing white and black seeds were kept in water for 5-6 hours. Black coloured seeds sank in the water and white ones were floating. Remove the floater and collect black viable seeds from the lower portion of the container and black colour showed germination about 80%. This simple process can help SFD & Farmers for large scale production of seedlings.
Application of this technique has enhanced seed germination and ease in seed separation of guggal seeds.
Ailanthus excelsa is commonly known as Ardu is moderate size, fast growing, and multipurpose tree species. It is highly valued as fodder, raw material for match box, making packing case and plywood. A. excelsa is a dioecious tree and sex expression can be known at flowering stage. This species possess natural variability and to exploit full worth/potential of plus trees, seed can not be used due to segregation of traits. It is very difficult to propagate A. excesla through stem cuttings as well as through micropropagation. In the above background, studies were taken up to clone selected male and female plants of A. excels through budding and grafting. One year old seedling were used as a source of root stock. One feet above the collar region, stem was cut by using grafting knife. Buds of a scion material were collected from the selected male and female tree and patch grafting was carried out in May-June in green house condition. To insure physical close contact with root stock and scion, peripheral portion was tighten using parafilm and plastic strips tied with thread. Success rate was about 50% and within 2-3 months plant were ready for the planting. Success of patch grafting was about 50% at nursery stage. To evaluate performance of budded plants, field trial was laid in AFRI experimental field and survival rate was 59% in male and 64% in female after 3 years. At 3 years age budded plant attained average height of 186 cm in male and 204 cm in female and collar diameter of 5.6 cm in male and 6.26 cm in female. There was no incompability factor observed in field. Female plant growth is about 10% more than male plants. There is no plagiotropic growth observed. This technique can be used for the establishment germplasm bank, clonal seed orchard as well as for production of clonal plants for increased productivity through plantations of A. excelsa.
Developed Prefined in vitro propagation protocol of Commiphora wightii (Guggal) through somatic embryogenesis
Commiphora wightii (Arn.) Bhandari (family burseraceae; vern. Guggal) is well known and over exploited for its oleo-gum-resin, which has very high medicinal value. Arid and semi-arid tracts of Northwest India are its natural habitats, where its population is seriously dwindling. The oleo-gum-resin is a complex mixture made up of various useful secondary metabolites. Two isomeric forms of a steroid -guggulsterone-E and guggulsterone-Z are the most sought after by the drug industry. These compounds are frequently used with combination of other supplements in curing the patients of cardiac dysfunction. The plant is now on the verge of extinction and listed as a threatened species in the IUCN Red Data Book. The reasons for threatened status are over-exploitation for the oleo-gum-resin through tapping leading to mortality, poor seed setting with low natural germination rate. A well standardized macropropagation protocol as well as an efficient and scalable in vitro mass propagation protocol for the plant had been lacking, which could give impetus to the specie restoration work.
In the backdrop of above problems, a refined protocol for in vitro propagation through somatic embryogenesis has been developed at AFRI. The protocol includes development of a selection procedure for identification of right stages of unripe fruits of C. wightii for obtaining the maximum numbers of immature embryos used for establishing the embryogenic culture. Initially, cultures were induced in 3-4 weeks on Gamborg's B5 medium supplemented with 2,4-D and further proliferated on the same medium for another 3-4 weeks. Non-embryogenic calli were converted to embryogenic through media manipulations in 6-8 weeks. Resulting embryogenic calli were maintained on modified MS medium, supplemented with BAP and IBA, for long term cyclic embryogenesis. Late torpetdo and early cotyledonary stage somatic embryos were regularly harvested from the modified MS medium every 3-4 weeks. Maturation of the embryos was a bottle-neck and was overcome through optimization of various factors. About 75% of mature somatic embryos germinated on modified MS medium. Germination initiates in a week and complete plants is ready in 3-4 weeks. Plantlets obtained were acclimatized and hardened which takes 3-4 months. A field trial consisting of 50 in vitro raised plants is being maintained at AFRI for performance evaluation. The survival rate of plants in the field in the initial six months is 100%. The complete protocol takes 8-9 months from culture initiation stage to field ready hardened plant production. This protocol has potential for rapid and mass production of Commiphora wightii for the production of planting material and conservation of germplasm.
Fig A-F: In vitro mass propagation of Commiphora wightii through somatic embryogenesis. A. Embryogenic callus; B. Multiplication of Somatic embryos (SE); C. SE maturation; D. SE germination; E. Hardening of plantlets; F. Hardened plants ready for out planting.
Prosopis cineraria L. is commonly known as khejri is a multipurpose State tree of Rajasthan. It provide fodder, fuel, imporove soil fertility, check soil erosion and life line of desert. During last decade, drying of khejri became a problem in the desert region and severity is upto 20% mortality of trees. Studies on the causal factors responsible for the large scale drying and the subsequent die-back of mature Khejri trees in north- western districts of Rajasthan have been conducted by the institute. It is closely examined that this devastating problem has primarily been posed with the cumulative effects of indiscriminate and successive lopping, followed by a secondary infestation of a shoot and root borers and fungi. The infected samples reveal the presence of root rotting fungi, Ganoderma lucidum and a root borer Acanthophorus serraticornis. This large scale mortality can be checked/ minimized by insect pest management.
Healthy khejri tree
Dead khejri tree
Ganoderma lucidum
Acanthophorus serraticornis
AFRI, Jodhpur has carried out studies on this problems and developed interim measures using prophylactic and control measures viz;
A gap of one year for Khejri lopping is advisable in order to recover from the injuries made by pests and diseases and only two third of the tree should be lopped, annually.
Soil treatment around 5 feet diameter area of soil from root using Bavistin (1ml/litre) + Chloropyriphos (1ml/litre) + Powermin (@2ml/litre). A quantity of 20 liters chemical suspension per tree should be applied. The treatment should be repeated at 6 monthly intervals.
The lopped portions/open wounds should be treated with AFRI PASTE just after lopping activity (One part of Copper Carbonate (1/2 Kg) + one part Red Lead (1/2 Kg) + Two part white petroleum jelly (1Kg) or 1.25ltr raw linseed oil and 3 ml Monocrotophos. (Modified Chaubattia paste) to check the fungal infection and egg laying by the shoot boring insects.
Severely infected and dried trees should be uprooted and the felled trees should be lifted from the vicinity immediately after their exploitation.
Demonstration trails for the management of khejri mortality has been carried out in Nagaur and Sikar districts in Rajasthan and proved quite effective as in interim measures.
Acacia nilotica commonly known as babul is timber species found in arid and semi arid region of Rajasthan. Defoliator severely damage the trees of A. nilotica and is severe problem. To over come this problem, studies were carried out on bio-control measures of leaf defoliator. Nuclear Polyhedrosis Virus (NPV) strains have been isolated and multiplied at large scale in Laboratory on healthy defoliator (Streblot siva). The NPVs were isolated from the host by purification, followed by differentiated centrifugation. NPV 106/ml in water effectively control the healthy population of the pest.
Rhizosphere soil samples were collected from forest nurseries and plantations of selected arid and semi-arid tree species from various districts/divisions from Rajasthan and Gandhinagar,Baroda,Rajpipla, Banaskatha in Gujarat.The rhizosphere soil samples were analysed for isolation of spores by wet sieving and decanting techinique. About 36 AM fungi were isolated and identified on the basis of size,shape,colour and attachment of subtending hyphae and with the help of synoptic keys available on taxonomy. Pure inoculums of most dominant AM fungi i.e., Glomus fasciculatum and G.aggregatum were prepared by collecting 500 viable spores by using funnel technique. Pure inoculums prepared by funnel technique was transferred to bigger pots by using autoclaved sand +soil mixture (1:1). Zea maize or Cenchrus ciliaris was used as a host for mass multiplication in pots and beds. Penissetum glaucum (Bajra) was also used as a host for mass multiplication of inoculumsa and it has reduced the multiplication period about one and half months earlier than normal course (use of maize or Cenchrus ciliaris as host).
The dose of inoculums was also standardized in forest species. 20 gm inoculums/plant in root trainer and 100gm inoculums in polypots/saplings containing 500 viable spores was found the best for growth and vigour of plants. The inoculums was applied by side banding method in root trainer and poly bags and soil mixing method in young saplings. VAM inoculation experiments in nursery and demo trials were laid out on various trees species in Rajasthan and Gujarat. The inoculated plants with VAM showed enhaced growth (35-40 percent) in all parameter and increase in p content in leaves. Training on VAM technology was imparted to forest officials of Rajasthan & Gujarat, NGOs and farmers time to time. Progressive farmers of Gandhinagar are using VAM inoculums in maize crop. Technology developed by the AFRI, Jodhpur has been used for the mass multiplication of VAM by the SFD Gujarat and used in nursery and plantations for the better survival and growth of the plants.
Establishment of VAM lab at Gandhinagar
VAM multiplication in pots
Training on VAM technology at Gandhinagar, Gujarat
In India, large chunk of area (6.73 mha) suffers from salt problem out of which Rajasthan accounts for 0.38 m ha. Salinization is the accumulation of soluble salts of sodium, magnesium, and calcium in soils. High levels of soil salts limit plant growth; the increased osmotic pressure of the soil solution reduces the plant's capacity to withdraw water from the soil. Utilization of these salt affected areas has become necessary owing to increasing need for fodder; fuel and other minor produce. Experimental trials were established on lithic, calcid, loamy sandy saline alkali medium to shallow depth soil at Gangani, Jodhpur to find out best performing plant species with suitable management practices.
Salt tolerate species viz; Plant Species Atriplex lentiformis, A. amnicola, Salvadora persica, Acaica ampliceps, Sueda nudiflora, Colophospermum mopane and Azadirachta indicia were tested with management practices of soil and water conservation, amendment of soil by the application of Gypsum, Compost, Urea and Calcium ammonium nitrate.
A. lentiformis survived well (upto 83%) on medium depth soil planted in normal pits with crescent drainage trenches. Double ridge mound, (DRM, adapted from Australia) technique enhanced the survival on shallow water logged saline soil. It responded to gypsum and nitrogen application and the treatment combination G1 (100 % soil GR + 60 g urea) was the best and produced maximum growth and the total green biomass yield (2.15 kg shrub-1) on relatively deep soil (60 cm) while on shallow soil (30-40 cm) gypsum even at 50% soil GR dose is sufficient.
A. amnicola (river salt bush) performed well on mounds under the water logged conditions maintaining 73.6 % survival on DRM , and 70.8% on Single Ridge Mound (SRM) and Bund after 72 months. 2.2 to 2.4 t/ha green biomass was obtained on Double Ridge mound (DRM) and bund structures while it was 0.98-1.4 t ha-1 on Single Ridge Mound (SRM) after three years of age. Tolerates medium grazing, but shrubs become woody with age and require fertilizer application after five years.
Atriplex spp has good re-growth potential after cutting. These shrubs produce nitrogen rich fodder (13.7 -15.8% CP) used for sheep and goat. It has high salt content (37.3-41.0 %) and hence is mixed with cereal residue.
Salvadora persica (L) is a preferential halophyte, evergreen multipurpose tree It stores excess salts in mature and senescent leaves and in the bark. Survival upto 85 %, despite deficient rainfall -including a severe drought, in different treatments after 72 months. Treatments positively influenced the growth and gypsum + 9g N was the best treatment attaining 207cm of height and 212cm of crown diameter, which was 38 % and 24 % more than the untreated plants. Fertilizer produced 12.0 kg/tree of fresh biomass, followed by 10.7 kg and 8.8 kg in treatment consisted gyp + 27g N and 9 g N respectively which was 71%, 53% & 27% more than the control (untreated plants). Crescent shaped drainage trenches for individual plants helped in plant establishment and growth serving the dual purpose of harvesting water and leaching salts. It has a very well developed root system with more horizontal and less vertical spread. After nine years of growth its root spread was more than crown spread. It is very good coppicer and generate multiple shoots in all the plant stumps.
Acacia ampliceps Maslin (exotic tree known as salt wattle), performs very well on deep alkali soils (soil depth 60 to 75 cm min). The overall survival was 76 % for gypsum treated plants as compared to 69% in control for deep soil area and upto 67.5 % in shallow soil area, respectively after four years of growth. The green biomass yield difference was more than two fold (12 kg tree-1 to 5.43 kg tree-1 for gypsum treated and 8.1 kg tree-1 to 3.9 kg tree-1 for untreated trees) for deeper and shallow soils at 60 months of age. It is a very good fodder for all the animals. However, it requires irrigation for survival during continuous drought. Roots did not penetrate the kanker pan spreading horizontally in the shallow soil.
Sueada nudiflora (succulent halophyte) is a perennial shrub species found on mud flats along sea coast or in saline soils in Gujarat and used as fodder for camel. In present study S. nudiflora recorded nearly 100% survival, attaining maximum growth. It produced maximum total dry biomass on all the three structures (2.16 tha-1 on DRM, 2.25 tha-1 on CDM and 1.09 tha-1 on control) after 36 months. At 72 months it recorded 79.2 and 66.7 % survival on CDM and DRM as compared to 55 % under control conditions.
Colophospermum mopane (glycophyte) proved to be ideal species for salty waste lands with 89 % mean survival after five years, surviving the drought and salinity stress due to its deciduous nature. Overall plants on CDM recorded a mean 1.45 kg green above ground biomass yield plant-1 which is 5.9% more compared to plants grown under control (1.37 kg). Application of Gypsum with 9 g N recorded higher biomass compared to all other treatments. Its roots penetrated the CaCO3 nodulated kanker pan further enhancing its utility. Produce protein rich fodder, leaf contain 9.2-13.0 % CP and 6.9% ash content. A very good coppicer, showing 100% re-sprout in the plants cut aboveground for biomass estimation.
Azadirachta indica (glycophyte) maintained good survival and growth initially (upto five years) on soil structures. A well developed root system was found on the CDM structure thus it has the potential to grow on saline alkali site with better irrigation regime from normal water.
Conclusions :
Salvadora persica, Sueda nudiflora (indigenous), and Acacia ampliceps, Colophospermum mopane (exotic) are the suitable tree species with different levels of management.
Atriplex spp. (exotic) adapted well among shrubs.
Soil and water conservation approach : Double ridge and Circular dish mound techniques enhanced the survival on shallow saline water logged area. Use of Gypsum (100 % soil GR), FYM and nitrogen enhanced growth (30-70%) depending upon treatments. This trial has been seen by officers of the SFD, Farmers and an similar line with minor modification laid in Kutch, Gujarat for habilitation of degraded site. Technology developed need to be replicated by the SFDs, Farmers, NGOs for in large area in salt affected region.
Scientific intervention in this trail has improved soil organic carbon matter, nutrient status, lowered pH and conductivity of the soil and increased biodiversity in the area. Growing grass as green fodder further support supply of fodder and income to the rural people.
Land scaping and plantation along road side of selected trees, shrubs/ornamental plants not only provide greenery, but also gives aesthetic, appealing view, apart from checking wind, soil erosion and also function as sink of carbon. AFRI has taken up three tier planting of trees and shrubs including Boganvellia in the sapcement of 3m x 3m. Out of the various species viz; Azadirachta indica, Acacia samia, Dalbergia sissoo, Tecomella undulata and Boganvellias, first tire of A. indica, second tire of Cacia samia, Dalbergia sissoo and Tecomella undulate and third tire of Boganvellia proved the best model. This model trial was irrigated by the sewage municipal water at the weekly interval. Survival rate was > 80% after 4 years. Based on this, it was replicated in other places in Jodhpur. Rajasthan Govt. has appreciated this model and directed in assembly that this type of model should be adopted in other cities in Rajasthan.
Volume tables, Site index equations, and growth & yield models (potential density, generalized height-dbh and basal area prediction models) developed for Azadirachta indica, E. hybrid and Acacia nilotica plantations in Gujarat and Tecomella undulata, Eucalyptus camaldulensis and Dalbergia sissoo plantations in IGNP area of Rajasthan. Anamorphic height growth models for Prosopis cineraria and Ailanthus excelsa, volume functions for A. tortilis and biomass equations for A. indica also constructed.
Site index curves for A. nilotica stands in Gujarat representing
Salt affected soils are usually degraded, bare and subject to wind and water erosion and hence require specific approaches for their reclamation and management to maintain their long term productivity. Therefore, technology developed for afforestation of lithic, calcid, coarse sandy to loamy sandy saline alkali soils. Planting of indigenous multipurpose halophytic tree, Salvadora persica, should be preferred for maximum survival. Combination of gypsum + 9g N is best for good growth and biomass yield. Shrubs of genus Atriplex, which produce nitrogen rich fodder used for sheep and goat, is suitable only if FYM and nitrogen is added. Acacia ampliceps is suitable for gypsum treated deep alkali soils giving better survival and biomass. Sueada nudiflora, species from mud flats and sea shore is suited for sandy saline soil. Double ridge and circular dished mounds (DRM & CDM) appreciably enhanced the survival of plants by providing protection from water-logging and less salty environment. Crescent shaped drainage trenches are helpful in leaching.
भारतीय वानिकी अनुसंधान एवं षिक्षा परिषद् (ICFRE) देश में वानिकी संसाधनों के सतत् प्रबंधन तथा विकास की दिषा में वानिकी अनुसंधान, शिक्षा, व विस्तार के समग्र विकास हेतु निर्धारित ध्येय आधारित कार्यक्रमों का क्रियान्वयन कर रही है।
