Agricultural sustainability through precision farming
M. S. Bajwa
The first phase of the Green Revolution was triggered in our country with the introduction of high-yielding varieties of crops, particularly wheat and rice. In Punjab, farmers rapidly adopted these varieties, which produced high yields by greatly responding to inputs like fertilisers, irrigation water, pesticides and energy.

Asia’s useful trees and plants
K. L. Noatay
Dhak or palas is a moderate-sized deciduous tree. Its scientific name is Butea frondosa. Some botanists also call it Butea monosperma. The family is Leguminosae-Papilioneae. Starting from Burma in the East, it is found growing throughout the Indian subcontinent, especially in Indo-Gangetic plains from 150 m to 1000 m or so above mean sea level. It is quite happy in black cotton soil as well and it is accordingly quite common from Sri Lanka north-wards i.e. the Indian Peninsula, especially the Decan Plateau.

Economic apple cultivation
V.P. Prabhakar
A low yield in apple was found in many orchards in Himachal Pradesh. The main cause for this was less of pollinisers (5 to 15 per cent). The number of the bee colonies was increased from O (control) to 8 per cent per hectare to compensate the availability of loss of pollinisers.

FARM OPERATIONS FOR JANUARY

Agricultural sustainability through precision farming
M. S. Bajwa

The first phase of the Green Revolution was triggered in our country with the introduction of high-yielding varieties of crops, particularly wheat and rice. In Punjab, farmers rapidly adopted these varieties, which produced high yields by greatly responding to inputs like fertilisers, irrigation water, pesticides and energy. The favourable public policies (credit supply, marketing, etc), generation of suitable crop production and protection technologies, and their adoption by the farmers further helped in making the Green Revolution a success. During this period, farmers have been progressively increasing cropping intensity with indiscriminate use of inputs without caring for the carrying capacities of different natural resources (soil, water, biodiversity, environment).

In Punjab, increasing intensification of agriculture in inherently poor soils (light texture, low organic matter, etc), inefficient and indiscriminate use of fertilisers, irrigation water, pesticides and energy have resulted in deterioration of soil physico-chemical properties, disturbance of water-balance, increasing problems of pest management, environmental degradation, etc. The shift in cropping pattern in favour of rice-wheat system has created additional problems of agro-ecological degradation. Because of the indiscriminate use of inputs, shrinking of natural resources and many other technology and public policy related problems, the cost of production has increased over the years resulting in deterioration of the economic conditions of the farmers.

The resource-poor, small and marginal farmers have particularly remained the worst sufferers. The impact of these factors has particularly been felt during the recent past because of the changing food and agricultural production requirements under the competitive and quality conscious world market (WTO effects). Our levels of agricultural production and market demands for quality products seem to have reached a stage where conventional farming system alone may not help in improving the economic conditions of the farmers. Even the intensively managed cropping systems are becoming unsustainable with respect to increasing profitability. It has, therefore, become imperative that the next phase of the Green Revolution must be triggered with a paradigm shift from the less efficient conventional farming towards the efficient precision farming system so that agricultural productivity and profitability are optimised.

Precision agriculture has, more recently, been capturing the imagination of all those concerned with profitable production of food, feed and fibre by efficiently managing each factor in the production system through holistic site-specific and eco-regional farm management strategies. The objectives of improving production and product quality and managing efficiently the inputs and natural resources are to be achieved through precise adjustments of different farm operations keeping in view the knowledge/information about in-field/in-farm/in/village variabilities in soil characteristics, cropping system, biotic and abiotic stresses, etc and the socio-economic needs of the people in different eco-regions. This concept does not involve changes in the agronomy and physiology of crop production but offers to intensively use modern information technology (IT) in conjunction with the traditional knowledge for maximising crop production efficiency, decreasing the production costs and minimising the negative environmental impacts.

The conventional farming system is still based on the use of generalised recommendations across the whole field or in all the fields of a farm/village/region. The wide variabilities (over distance, depth and time) in soil characteristics, moisture-retention, topography, plant growth, pest populations, etc are ignored. This results in over-application of inputs in some fields (decrease in profit margins) and under-application in others (decrease in yield and quality). The conventional system has also not been able to efficiently take care of the post-harvest handling and the marketing of the produce. There are many other such types of examples because of which agricultural productivity and profitability under the conventional farming are becoming unsustainable.

The precision management strategy requires efficient adoption of a suite (package) of technologies rather than a single technology, because of the involvement of a number of farm operations, such as land preparation (levelling, tillage, management of crop residues, etc), planting/sowing (crop/variety selection, seeding, etc), management of inputs (rates, time and method of application), harvesting and processing (time, grading, etc), marketing (demand — driven, quality of the produce, market intelligence), and many others. The precision farmers have to quickly and precisely make decisions about when, where, how and how much to perform these operations in each field so as to reduce wastages and losses, and ensure profit maximisation and protection of agro-ecosystem. For example, specific crops and their varieties have to be selected for each region keeping in view the site-specific biotic and abiotic stresses to reduce field-to-field or regional imbalances in crop yields. Since crop responses to applied fertiliser use has always to be soil-test basis, site specific (based on soil fertility status) judicious use of nutrients is to be made following the best dose, time and method of application to increase fertiliser use efficiency, decrease cost of production and check soil depletion. Soil physical properties (texture, compaction, water retention etc) and tillage needs greatly vary even within the same field, and hence require to be managed differently.

Hefty subsidies of electricity for pumping of water for irrigation of crops have led to inefficient use and over-exploitation of the groundwater. The resultant input/output imbalance has caused depletion of groundwater in some regions and waterlogging and salinity in others. The efficiency of conventional surface irrigation method is also very low (less that 50 per cent), which can be increased up to 90-95 per cent) by furrow, sprinkler, and drip irrigation. Irrigation schedules for different crops have to be followed efficiently for conserving water and increasing water use efficiency. Pest (insects, diseases, weeds) incidence greatly varies under different cropping systems, weather/climatic conditions, levels of applied irrigation and fertilisers, etc. However, recommendations about the use of pesticides are made on the basis of random pest-infestation observations. This results in indiscriminate pesticide use, which can increase resistance of pests of pesticides and encourage pesticide-induced resurgences of pests. Up to 80 per cent of the applied pesticides (spraying method) do not reach the target site. Precision farmers use the right kinds and doses of pesticides with right kind of spraying equipment at the right time and get maximum benefit from the pesticide and also check environmental pollution.

The improvements in input-use efficiency will check environmental degradation and also improve quality of the produce. These farmers will ensure profit maximisation from each field through (i) higher productivity with the same level of input (ii) the same productivity with lower level of input, and (iii) higher productivity with reduced level of input. The extent of total economic benefits will, however depend on the extent of variabilities in different factors of crop production and the efficiency with which different farm operations are performed.

(To be continued)

Asia’s useful trees and plants
K. L. Noatay

Dhak or palas is a moderate-sized deciduous tree. Its scientific name is Butea frondosa. Some botanists also call it Butea monosperma. The family is Leguminosae-Papilioneae. Starting from Burma in the East, it is found growing throughout the Indian subcontinent, especially in Indo-Gangetic plains from 150 m to 1000 m or so above mean sea level. It is quite happy in black cotton soil as well and it is accordingly quite common from Sri Lanka north-wards i.e. the Indian Peninsula, especially the Decan Plateau.

The bole of dhak is seldom straight and the branching too follows no particular pattern. Growth-wise it is quite slow growing and attains a height of about 5 to 8 m and diameter of about 20 to 40 cm (at breast height) when mature at the age of about 50 years or so. The bark of dhak is fibrous and bluish grey to light brown in colour. It exudes a kind of red juice if and when injured. That dries into very useful gum.

The leaves of dhak are compound. Each has three leaflets. The texture of the leaflets is fairly tough. These are coriascious with the surface glabrescent above and hairy silken beneath. The size varies from 15 cm to 20 cm by 10 cm x 15 cm. The shape is obliquely ovate and broadly elliptic. The leaves fall off by November-December and reappear during spring i.e. March-April. In between the tree remains leafless, when it bears beautiful pink to red-coloured flowers. These start appearing in February and stay on nearly up to the end of April. The size is nearly 2 to 4 cm in diameter. These tend to be densely crowded on leafless branches. The calyx i.e. the lower whorl of the flower tends to be darkish grey like the supporting branch itself. The upper parts are brick red. These give the plant so handsome a look despite it is leafless during spring season when entire terrain having dhak trees wears a kind of exquisite pink hue. A tract, in fact presents a picture like the forest being on fire. According the tree is sometimes called as "flame of the forest".

The fruit of palas is a flat legume — a pod, nearly 15 cm long and 3 to 5 cm wide. Young pods have a lot of hair — a velvety cover. The mature pods hang down like peculiar legumes.

Dhak is a very useful plant in a number of ways. Its leaves are essential for various rites in Hindu homes, like yajnas, havans, etc. These are also used for making cheap vegetative leaf plates and cups for rural feasts. In some parts of the country these are used for wrapping tobacco to make biddies. These are further used as packing material for parcels. The cattle also eat the dhak foliage quite greedily.

The bark of dhak yields a kind of coarse and brown coloured fibre, which is used for rough cordage. The juice exuded by the bark hardens in to ruby coloured gum beads. It is akin to ‘kino’ gum of the trade, and is used as substitute for the same. It finds use for caucking boats as well. The dhak flowers yield an orange dye. A preparation of the same is used as an insecticide. The seeds are used in ayurvedic practice and Unani hikmat for treating a large number of human maladies and light food for the sick. The dhak tree acts as a host for lac insect and is, therefore, useful in producing natural lac.

The wood of dhak is greenish white in colour. It is porous and soft in texture and has annual rings — though not very distinct. Density and texture-wise, the wood is soft in that it weighs about 14 to 15 km per cubic foot. It generally perishes fast when used at sites open to vagaries of weather, but gives better durability when used under water. It is accordingly used for making well curbs and piles.

Regeneration wise, dhak comes up naturally and easily in mixed deciduous stands in temperate forests. As such much research has not been done on its artificial regeneration. It is seldom planted artificially, perhaps because it gives so forlorn a look, especially when leafless. It may also not be very profitable or even practical to raise its seedlings in nurseries. Nevertheless, keeping various utilities of the tree in view, the plants coming up naturally in forest lands and elsewhere deserve to be given due protection.

Economic apple cultivation
V.P. Prabhakar

A low yield in apple was found in many orchards in Himachal Pradesh. The main cause for this was less of pollinisers (5 to 15 per cent).

The number of the bee colonies was increased from O (control) to 8 per cent per hectare to compensate the availability of loss of pollinisers. These studies, according to the annual report of the Indian Council of Agricultural Research for 2000-2001, revealed increased fruit set from 20. 32 to 47.43 per cent with an increase in the number of apis mellifera colonies.

With cm increase in the number of bee colonies, according to the report, from 0 to four per hectare in orchards having sufficient pollinisers (30 per cent), fruitset increased from 32.48 to 53.55 per cent. Thus, for getting economical crop of apple, eight apis mellifera colonies per hectare are needed in orchards having low polliniser proportion and two colonies per hectare are sufficient for orchards with adequate pollinisers.

Now, the orchardists make it a point to get bee colonies on rent (Rs 300 to Rs 350 per colony) for pollination in the Kulu area of Himachal Pradesh. In some villages community approach has been adopted where all the required colonies are obtained for a village by pooling money.

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A noble technique to reduce labour expenses for hand pollination, the report says, has been employed in sunflower hybrid pollination in Andhra Pradesh. Apis mellifera colonies were placed in female line plots and bee forages were employed for pollen dispersal. Pollen from male plots were collected and kept in the cavities at the hive entrance. Pollen can be collected by a suction pump mechanically. The outgoing bees to female plots got smeared with pollen-grains and proved very effective in pollination, giving a tonne seed yield per hectare as against 1.05 tonnes by the hand pollination.

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Under the all-India coordinated research project on renewable resources of energy, Punjab Agricultural University, Ludhiana centre, has developed a 10-KW capacity wood-based down draft gasifier. Based on the requirement of an industry for thermal application, the design was scaled up to 20-KW capacity and a matching gas burner was designed.

The system was reported working satisfactorily, delivering 289 MJ/hr (69,000 kCal/hr) of heat output with approximately 80 per cent thermal efficiency. The gasifier, according to the report, has so far operated for a period of 1400 hr.

An investment of approximately Rs 40,000 was made on 50 per cent cost sharing basis by the industry for the installation of the gasifier. An economic appraisal of the complete system revealed that hourly energy cost of the existing system was around Rs 128 while that of the gasifier system Rs 70, thereby resulting in a saving in energy cost to the extent of Rs 58 per hour. The payback period for one and two shift operations of the industry was computed to be 10 and 5 months, respectively.

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Liberalisation of agricultural trade and price stability: Integration of the Indian agriculture with global market has raised serious concerns about price stability, vulnerability of small and marginal farmers to price shocks, and inter-regional distribution of trade gains and losses.

A study on price behaviour of wheat, rice, maize, sorghum, soyabean and sugar since 1950 showed cyclical pattern in international prices. The instability, according to the ICAR report, in international prices has risen sharply after 1970. Except coarse cereals, domestic prices have exhibited far less instability than international prices. If international price shocks are transmitted to the farm level prices, it would destabilise the crop pattern and supply.

The cost of such shifts in terms of crop specific farm investments, arranging seeds and other inputs, production and marketing skill would be prohibitive for the majority of marginal and small farmers. Since under WTO obligations such temporary imports and shocks cannot be checked through quantitative restrictions, there is a need for alertness to impose appropriate tariffs to regulate unwanted imports.

The impact of trade liberalisation, however, would vary from state to state. Combined impact of free trade in rice and what through export would be beneficial to Punjab, Haryana, Uttar Pradesh, West Bengal and Madhya Pradesh. Similarly, trade liberalisation in edible oil and pulses would have adverse impact on net social welfare in Rajasthan, Madhya Pradesh, Gujarat and Haryana.

— Pruning of deciduous fruit trees like peach, plum and pear should be carried out during January. For grapes the pruning is normally initiated in the second fortnight of January and completed by the first week of February.

— The deciduous fruit plants like peach, plum and bare-rooted ber can be planted up to the second fortnight of January, while pear and grapes are planted in the first fortnight of February before they start new growth.

— Protect the young plants from frost and mend thatches where required.

— If the growers have not applied farmyard manure and fertiliser to the frost plants last month, it should be given now. Apply the farmyard manure, superphosphate and half nitrogen and half potash to the grapes after pruning.

— One irrigation should be applied to the ber trees during this month as the fruits are in the developing stage.

— The best time for harvesting kinnow fruits starts on January 15. For the fruits intended to be consumed after more than 10 days, individual seal packing should be done. Use high-density polythylene bags for individual packing of kinnow fruits and seal the open by heating or with rubber band after narrowing and twisting it.

— To rejuvenate the declining citrus orchards after harvest, remove the dead wood during January-February before the new growth starts. Apply Bordeaux paste to the cut ends and trunk of the trees followed by Bordeaux paint. After one week, Spray the crop with Bordeaux mixture (2:2:250).

— Trees of inferior varieties of peach, plum and mango may be headed back now. These trees will give out new shoots which could be budded in February-March with superior scions.

— Bark eating caterpillar in citrus should be controlled by removing the webs and filling the holes with kerosene during January-February as was done in September-October. Treat all alternate host plants in the vicinity. Treat foot root/gummosis and canker in citrus by decortication and disinfection of wound on the trunk with Bordeaux paste. After the paste dries up in about a week, apply Bordeaux mixture (2:2:250).

— Nymphs of mango mealy bug should be prevented from crawling up the trunk by applying a slippery or sticky band one metre above the ground level.

— Pear diseases, phoma leaf spot and black mould of ber can be checked by spraying the trees with Bordeaux mixture (2:2:250) or 0.3% copper oxychloride 50% in 500 litres of water.

— To keep off foot rot or collar rot of grapewines, plant cutting after dipping in 0.2% Ziram suspension.

Regular watering and occasional weeding may be carried out. Most of the varieties of winter season annuals must have started flowering and some of them may be in their full bloom. Tall growing annuals like Dahlia may require support of stakes for their proper upright growth. Seasonals planted in pots can easily be protected from sold injury by shifting to some sunny and protected spots.

Almost all the varieties finish their flowering by the end of this month. Plants of selected varieties which are required for getting cuttings in the next season may be cut back by keeping 4-5 cm height from the ground.

Continue removing faded out flowers and suckers to improve the quality of new blooms. Propagation of new plants can be carried out but the rate of growth will be quite low.

Save from cold injury, particularly during night time. Water regularly, liquid cow dung manure may be added to the weak premanent potted plants.

The deciduous plants (which shed their leaves in winter) can be transplanted before they start sprouting without any earth ball. Similarly, pruning and training of deciduous plants may also be carried out before they start sprouting. Tree pits can be prepared for plantation of all types of permanent plants in February-March.

— Progressive Farming, PAU