From Crisis to Conservation: Punjab's 2009 Water Act and Its Impact

From 1998 to 2018, the average annual rate of fall in the water table of Punjab was 0.53 meters. The situation in some central districts was worse as the rate of water table went to more than 1.0 meters per annum. The management of paddy straw also became an important issue in the context of environmental concerns at national and global levels.

Additionally, the increased incidence of insect pests and diseases also necessitated appropriate measures. Eminent scientists in the past years have emphasized decreasing area under rice cultivation in the state, however, favorable policies, less vulnerability to weather vagaries, and amenability to mechanization make it the preferred Kharif crop among the farmers.

Though efforts to bring down the acreage under rice are necessary, the optimization of sowing/ transplanting dates can provide much-needed immediate intervention to address the above concerns. Punjab Agricultural University (PAU), Ludhiana, since its inception, has been instrumental in the development of high-yielding varieties of rice along with matching production and protection technologies as well as providing realistic inputs to the policy support concerning the preservation of natural resources, particularly underground water.

Time and Water Requirement

The water requirement of rice is functionally dependent on transplanting time. Rice transplanting early in the season, under higher evaporative demand and no rainfall, leads to the extraction of a significant amount of groundwater. In various rice-growing agro-climatic zones of Punjab, the average annual rainfall ranges from 350 to 700 mm, while the water requirement of rice ranges from 1200 to 1500 mm depending upon varietal duration and transplanting time. To reduce the load on underground water, transplanting rice close to the onset of monsoon is an important step and for these policies leading to the regulation of transplanting date can play a vital role.

As per the research conducted at PAU, the Punjab Government issued an Ordinance in the year 2008 and an Act “Punjab Preservation of Sub-soil Water Act Punjab (2009) that restricted nursery sowing/transplanting of rice before May 10/June 10. The act was revised to May 15/June 15 in the year 2014. This did not cause any yield handicap. Rather, record yields were observed in 2016 and 2017. During these years, the shorter duration varieties became available, offering the opportunity to shift the transplanting start date further close to the onset of monsoon, and the transplanting date was shifted to June 20, 2018. This became possible mainly with the development and enthusiastic adoption of short-duration rice varieties by the farmers which performed better under staggered transplanting dates (Table 1). Through effective implementation of this act, estimates show that the fall in the water table has been checked to an extent, however, further measures are necessary.

Short-duration Varieties for Straw Management  

The data from PAU research experiments and farmer participatory surveys reveals that short-duration varieties of paddy consume 5-9 less irrigations and require less fertilizer and pesticides etc. In the last 10 years, PAU has recommended a dozen short to medium-duration rice varieties. The adoption of these resource-use-efficient varieties on a wide scale has not only increased production but also has set records in terms of productivity and contribution to the central rice pool. It is evident from the data that medium-duration varieties are giving good yields under June 25 transplanting.

The short-duration variety (PR 126) has been found to yield even better under July transplanting (Table 1), resulting in substantial savings of irrigation water (6 to 17% over the early date). The strict compliance of the act has shown significant positive effects in terms of arresting the decline in the water table and enhancing productivity (Table 2). Moreover, owing to their shorter duration, these varieties provide more window periods between harvesting of paddy and sowing of rabi crops; and have lesser straw yield (Table 3) making them amenable to efficient straw management.

Impact of Transplanting Time on Insect Pest and Diseases

Transplanting of rice early in the season is likely to aggravate damage by insect pests due to continuous host availability. Further, the migration of pests and diseases can cause devastation in the relatively late sown crop. This has been noticed particularly in the case of yellow, white, and pink stem borers of rice in studies conducted at PAU, Ludhiana. The heavy buildup of pests like stem borers and plant hoppers poses a serious threat to the Basmati crop, which is transplanted late. This leads to excessive pesticide usage, which may result in pesticide residue issues, thereby hampering the export potential of Basmati rice. The buildup of pests on rice crops beyond a threshold can also prove to be a threat to succeeding wheat crops as happened in the case of pink stem borer after the 2019 rice harvest. Moreover, diseases like false smut and sheath blight also show more severity in early transplanted rice.

Southern Black Streaked Dwarf Virus

It is a new viral disease observed during Kharif 2022. Although in 2023 there were no reports of this virus, farmers are advised to keep surveying the fields right from nursery sowing to check plant hoppers (white-backed plant hoppers) that spread this disease. For insect surveillance, light a bulb near the nursery/field as the insects are attracted to light during the night. Upon the appearance of plant hoppers, spray any of the insecticides for control of white-backed plant hoppers. Avoid early nursery sowing (before 25 May) and early transplanting (before 25 June) as it was noticed that stunted plants were comparatively less in late transplanted rice (Table 1).

It is thus evident that the early sowing/transplanting date is not advantageous from the economic, ecological, and social fronts. So, farmers should adopt staggered sowing/transplanting of rice as per the guidelines provided in the “Punjab Preservation of Sub-soil Water Act Punjab (2009)” and the Package of Practices of PAU for economic and eco-friendly rice cultivation.

Table 1. Grain yield (kg/ha), water saving, and incidence of virus disease (%) under different dates of transplanting (Average of 3 years)

*Data averaged across varieties during 2022

Table 2: Trends in productivity over the years in connection with transplanting dates

Table 3: Grain yield and window period availability under different paddy varieties

#Long duration variety adopted by farmers; not recommended by PAU