Experiences of the under developed countries of the world justify the operation of this law in agriculture. Phenomenon of disguised unemployment revealing zero or near zero or negative marginal productivity of labour is one such example. Withdrawal of disguised unemployed people and employing it in industrial sector can increase the output of agriculture.
Agricultural production and productivity can be substantially increased by making advancement in agricultural technology through progress in science. Scientific rotation of crops, improved seeds, fertilisers, modern implements, better irrigation facilities, etc. are some ways in which this can be done.
This will also solve the problem of food crises and starvation. Most of developed countries of the world have been successful on this front. However, technology advancement shifts the total product curve upwards. It will just postpone the operation of this law and eventually diminishing returns will set in. Thus, the application of the law of variable proportions is inevitable, inexorable and all pervading.