The state with the lowest child sex ratio is Haryana. The child sex ratio is the number of girls per 1000 boys in the age group of 0-6 years. In Haryana, the child sex ratio has been declining over the years and currently stands at 834 as per the 2011 Census.

Reasons for low child sex ratio in Haryana:

1. Patriarchal society: Haryana has a deeply rooted patriarchal society where male child is preferred over a female child. This can be attributed to the age-old belief that the male child is responsible for carrying the family name and also for performing the last rites of the parents.

2. High prevalence of female foeticide: Despite the Pre-Conception and Pre-Natal Diagnostic Techniques (Prohibition of Sex Selection) Act, 1994, which prohibits the use of sex determination techniques, female foeticide is still prevalent in Haryana.

3. Preference for son: The preference for a son is so high in Haryana that families often resort to illegal means to ensure the birth of a male child. This includes sex-selective abortions, infanticide, and neglect of female children.

4. Low status of women: Women in Haryana have a low status in society and are often subjected to discrimination and violence. This leads to a lack of access to education and healthcare, which further perpetuates the problem of low child sex ratio.

Steps taken by the government to improve child sex ratio:

1. Beti Bachao, Beti Padhao: This is a flagship programme of the Government of India launched in 2015, which aims to address the issue of declining child sex ratio and empower girls through education.

2. Strict implementation of PCPNDT Act: The government has taken steps to curb the practice of female foeticide by strictly enforcing the Pre-Conception and Pre-Natal Diagnostic Techniques (Prohibition of Sex Selection) Act, 1994.

3. Awareness campaigns: The government has launched various awareness campaigns to sensitize people about the importance of the girl child and the need to eliminate discrimination against women.

In conclusion, Haryana has the lowest child sex ratio in India, which can be attributed to the deeply ingrained patriarchal mindset, the high prevalence of female foeticide, and the low status of women in society. The government has taken steps to address this issue, but a collective effort is required from all sections of society to eliminate discrimination against women and ensure that every child, irrespective of gender, is given an equal opportunity to thrive.