Cow Agriculture or Organic Agriculture in Rigveda

जैविक कृषि एती मे गावौ प्रमरस्य युक्तौ मो षु प्र सेधीर्मुहुरिन्ममन्धि। आपश्चिदस्य वि नशन्त्यर्थं सूरश्च मर्क उपरो बभूवान्‌।। RV 10.27.20
jaivika kṛṣi etī me gāvau pramarasya yuktau mo ṣu pra sedhīrmuhurinmamandhi| āpaśchidasya vi naśantyarthaṃ sūraścha marka uparo babhūvān‌|| RV 10.27.20 

Farmlands with cows retain water and maintain healthy soil organisms, with twin bounties. 

गौ गोमूत्र और गोबर से भूमि के हानिकारक कृमी का विनाश और भूमि को उर्वरकता प्राप्त होती है, जैसे सूर्य और वर्षा के जल से होता है। RV10.27.22
Gau gomūtra aur gobar se bhūmi ke hānikārak kṛmī kā vināś aur bhūmi ko urvarakatā prāpt hotī hai, jaise sūrya aur varṣā ke jal se hotā hai| RV10.27.22 

The urine and dung of cows, eliminate harmful microorganisms and keep the soil fertile like sun and rains make the land free from harmful pests make it fertile.

गौ की ध्वनि से कीटाणुओं का विनाश होता है उत्पादन बढ्ता है वृक्षे वृक्षे नियता मीमयद्ग्नौ–स्ततौ वय: प्रपतान् पूरुषाद:। RV 10.27.22
gau kī dhvani se kīṭāṇuoṃ kā vināś hotā hai utpādan baḍhtā hai vṛkṣe vṛkṣe niyatā mīmayadgnau-statau vay: prapatān pūruṣād:| RV 10.27.22 

Sounds made by the cows free the trees from vegetation of pests, and promote growth. 

गोमूत्र गोबर जैविक उर्वरकता के पोषक देवानां माने प्रथमा अतिष्ठन् कृन्तत्रादेषामुपरा उदायन्‌। त्रयस्तपन्ति पृथिवीमनूपा द्वा बृबूकं वहत: पुरीषम्‌।। ऋ 10.27.23. 
gomūtra gobara jaivika urvarakatā ke poṣak devānāṃ māne prathamā atiṣṭhan kṛntatrādeṣāmuparā udāyan‌| trayastapanti pṛthivīmanūpā dvā bṛbūkaṃ vahata: purīṣam‌|| ṛ 10.27.23.  

Cow dung & urine has links to Carbon Nitrogen Cycle 

अथेद विश्व भुवनं भयात इन्द्राय सुन्वदृषये च शिक्षित्‌।
atheda viśva bhuvanaṃ bhayāt indrāya sunvadṛṣaye cha śikṣit‌|

We are grateful to Indra for the land link of Carbon and nitrogenous fertilizers in the ecological system.

Cow Promotes Health, intellect and positive attitudes,

अयं स शिञ्क्ते येन गौरभीवृता मिमाति मायुंध्वसनावधि श्रिता। सा चित्तिभिर्नि हि चकार मर्त्यंं विद्युद् भवन्ती प्रति वव्रिमौहत।। RV 1.164.29, AV 9.1 0.7.
ayaṃ sa śiñkte yena gaurabhīvṛtā mimāti māyuṃdhvasanāvadhi śritā| sā chittibhirni hi chakār martyaṃṃ vidyud bhavantī prati vavrimauhata|| RV 1.164.29, aV 9.1 0.7. 

In the land immersed in the sounds made by cows ensconced in comfort and affection, the temperaments of men become introspective, looking to the welfare of the downtrodden, but highly self-motivated, as if they are electrified in the execution of deeds of harmony and beauty. The soil mixed with cow dung, cow urine, and the warmth of sunshine make lands fertile and bring prosperity.