Tamāla Kṛṣṇa: "Bhoktāraṁ yajña-tapasām (BG 5.29). Therefore ultimate satisfaction of the Lord is the chief purpose of all yajñas. When these sacrifices are perfectly performed, naturally the demigods in charge of the different departments of supply are pleased and there is no scarcity in the flow of natural products."
Prabhupāda: Yes. Because after all, however tractor, machine, or farm arrangement you may make, unless there is supply of heat and water, it is all useless. You cannot produce grains just like wheat or rice or pulses(?) in your factory or by your will, defying the nature's law. Oh, that you cannot do. Real, your life is in the hands of the demigods. If they stop supply, sunshine, if they stop supply, water supply, how you can produce? Therefore you have to satisfy them. People have practically forgotten their duty.