PRACTICAL, PRODUCTIVE AND ENVIRONMENT FRIENDLY

UTILIZATION OF SALT AFFECTED SOILS IN PAKISTAN

By: Farooq et al; PAEC,

Islamabad, Pakistan

The topic of soil salinity is so wide and diversified that probably every body sitting in this hall has his/her own salinity Problems,Perception,Solutions and the way ofUtilization

Hence every effort in its own perspective has to be practical and productive and probably

environment friendly too

INTRODUCTION

In Pakistan• Climatic conditions are arid and semi arid• Very high temperature in central and Southern parts• Frost in central and Northern parts• Mini. rainfall of 250 mm in 68% of geographical area• Maxi. rainfall of 550 mm in 24% of geographical area• Monsoon* rain in July and August• Winter rains** in Northern and Western part

*,** Now scanty and rare, respectively

Major Problems

1. Drought: Created by low precipitation, high heat and evapo-transpiration and shortage of irrigation water;

2. Salinity: Created by seepage of water from canals, and rivers and high

evaporation which has affected 6.3 Mha of land

The entire 6.3 Mha of saline soils are divided into three general types i.e. i) Saline soils in irrigated areas, ii) Saline soils in water deficit and /or dry areas, and iii) Saline soil in desert areas. Type-i soils possess electrical conductivity (EC) in the range of 10 to 15 dSm-1, are found saline sodic through out root zone, can be easily drained, and possess good physical qualities. The extent of these soils is 4.79 Mha of which one Mha is under wheat cultivation and require salt tolerant wheat genotypes

Type-ii soils, that are in water deficit/dry areas, are also beset with desertification such as those located in Southern Punjab and some parts of Sind Province.

The average temperature during wheat season in these areas ranges between 19-32 0C and average annual rain fall between 0.19-35mm.

These soils possess EC in the range of 6-10 dS m-1 and exist as patches. The extent of such soils in Pakistan is 1.5 Mha and can be cultivated with high yielding salt tolerant genotypes that may also tolerate water deficiency and high temperature.

Type-iii soils, which are present in desert areas are peculiar to semi arid zones comprising Cholistan, Thar, and Kharan.

These soils are beset with high rate of evaporation and strong summer winds. Water is most critical and limiting factor that prohibits using such areas for agricultural production.

These soil requires genotypes that can be grown without much water, can sustain strong winds and

provide green cover to barren lands thereby protecting it from the wind erosion.

The problem however, is that all these soils are not similar in nature. There are highly significant differences in

i.Composition, type and quantity of predominant salts in a particular area, ii.Climatic conditions, availability and type of irrigation water and iii.Co-existence of salinity with desertification.

Hence, it is imperative to tailor plantsspecifically suitable to such conditions and

others as well

 

MATERIAL S AND METHODS

Material used in this study comprised short stature line (SSt), drought tolerant line

(DTL), and “DURUGEN” which combines both salt and drought

tolerance.   

DTL was produced by crossing WL-1076 with a water

deficiency tolerant accession of Aegilops geneculata. F1 was back crossed with recurrent

wheat parent and selfed 6 times before DTL was tested in the

field for salt tolerance.  

RUSULTS

SSt was produced for type-i saline soils present in the districts of Rahim Yar Khan in Southern and Kamalia in the central Punjab where wheat-cotton rotation is being practiced. It was sown at the end of January after picking last lint of cotton. In 90-100 DAS, SSt plants on the average attained •18 inches of height, • produce 24-30 productive tillers, and • grain yield of about 3000 kg ha-1 instead of 1000 kg ha-1of commercial cultivar. Getting this much yield in 100 days compared to 155-160 days of

commercial cultivars was never possible without SSt.

Typical SSt plant with short stature and heavy tillersTypical SSt plant with short stature and heavy tillers

DTL was developed for type-ii saline soils located in districts of Bahawalpur, and Rahim Yar Khan in the southern Punjab and some parts of Sind Province.

These areas have twin problems of salinity and water deficiency At Rahim Yar Khan, genotype on the average possess• 100 cm long plant height, • >21 productive tillers plant-1 and • grain yield of 4000 kg ha-1 which is 10% higher than the yield obtained from the local check.

16

A typicalA typicalDTL DTL plantplant

Heavy wax Heavy wax can be seen can be seen

on the on the leaves and leaves and

stemsstems

DTL is being tested under simulated fieldconditions

DTL is being grown in the field

DTL is growing at Multan

DURUGEN was developed for type-iii saline soils that are coupled with desertification, high temperature, strong winds, and are mostly located in Thal, Thar, and Kharan, The conditions there are so harsh that the inhabitants have largely been migrated to

other places in search of livelihood.

Simulated field trials of first generation “DURUGEN” produced • 6-26 tillers, • 4-20 spikes, • 60-90cm plant height, • 55-90 grams of plant weight, • 15-23 grain spike-1 and • 2.2-6.3 grams grain weight spike-1.

The second generation plants when tested using 50% less irrigation water and salinity of EC 15dS m-1 indicated significantly lower

reduction (10-12%) in biomass and (5-8 %) and in grain yield than that (37% and 23%, respectively) observed in check varieties grown

under similar conditions.

DISCUSSIONIt is generally believed that solution to salinity depends upon:

Gravity of the situation, Resources of the country, Priority of the agriculture sectors, Environmental conditions, and Social acceptance of the approach in term of economic benefits

Gravity of situation in Pakistan 6.3 Mha of land is affected by salinity One of the priorities of agriculture sector is achieving wheat production target of 26.50 M tons There are about 4.1 million small farmers watching their land being degraded due to salinity, drought, and/or water deficiency, Water is 35-40% less than it was available previously, Most of the water deficient areas are also beset with high temperature

Farmers want to see their lands productive with minimum investment in order to ensure food security to their families

Added to this is

•Pakistan’s current population which is over 156 M, •Current figure of undernourished people which is between 35-40% •Require more food calories to reduce the number, and hence need to increase wheat production (major staple cereal) from 23.4 MT to 26.50 MT

which is possible by using saline lands

For example, SSt was developed for saline areas that are canal irrigated and are used for wheat-cotton rotation. The extent of such soils in Pakistan is 4.79Mha of which 2.89 Mha became saline due to irrigation provided by subsurface saline water. If SSt can be cultivated on only one Mha of this area, it would produce approximately 3 MT of extra wheat which can increase consumption of calories by the poor inhabitant of saline lands.

DTL is an improved version of low input WL-1076 which possess proven potential to be cultivated on saline/water deficit areas of Bahawalpur, Rahim Yar Khan, and Multan where farmers can provide only 2-3 irrigations (instead of at-least 5 given to commercial cultivars)

In Bahawalpur region, farmers obtained grain yield of 4000 kg ha-1 that was 10% higher than the commercial wheat cultivar that is input intensive and the resource deficient farmer can not afford to cultivate this due to shortage of water and inadequate and expensive fertilizers which are largely imported.

Potential of DURUGEN has indicated that if cultivated in desert areas, the farmer at-least can get green cover on the barren lands which can prevent erosion caused by strong winds thereby improving the desert environment.

It can also provide some fodder for the animals which is enough attraction for re-habilitating these soil and their owners to

their native place.