Prayer Books have always contained a section of extra collects and prayers on various subjects. Most of the historic Prayer Books have placed them after the Morning Office, with the intention that they be used as additions to the Office.
The 1979 Prayer Book (and presumably the 2019 book also) did something different. On the plus side, the collection of additional prayers and thanksgivings was vastly expanded and indexed for ease of use. On the negative side, they were placed as a sort of appendix towards the very back of the book such that there was no clear implication that they are meant to enrich and expand the Daily Office.
Since Saturday is a common day of rest for many, for families to gather, to enjoy the outdoors, perhaps this is a good opportunity to use prayers #26-30, for the Natural Order! You can find the full list of Occasion Prayers and Thanksgivings here. Or, here are the prayers concerning the natural order:
26. For Joy in God’s Creation
O heavenly Father, you have filled the world with beauty: Open our eyes to behold your gracious hand in all your works; that, rejoicing in your whole creation, we may learn to serve you with gladness; for the sake of him through whom all things were made, your Son Jesus Christ our Lord. Amen.
27. For Stewardship of Creation
O merciful Creator, your hand is open wide to satisfy the needs of every living creature: Make us always thankful for your loving providence; and grant that we, remembering the account that we must one day give, may be faithful stewards of your good gifts; through Jesus Christ our Lord, who with you and the Holy Spirit lives and reigns, one God, for ever and ever. Amen.
28. For the Harvest of Lands and Waters
O gracious Father, you open your hand and fill all living things with plenteousness: Bless the lands and waters, and multiply the harvests of the world; send forth your Spirit, and renew the face of the earth; show your loving-kindness, that our land may yield its increase; and save us from selfish use of what you provide, that men and women everywhere may give you thanks; through Jesus Christ our Lord. Amen.
Or the Collects assigned for Rogation Days
29. For Rain
O God, our heavenly Father, by your Son Jesus Christ you have promised to those who seek your kingdom and its righteousness all things necessary to sustain their life: Send us, we pray, in this time of need, such moderate rain and showers, that we may receive the fruits of the earth, to our comfort and to your honor; through Jesus Christ our Lord. Amen.
30. In Time of Scarcity and Famine
O God, our heavenly Father, whose blessed Son taught us to seek our daily bread from you: Behold the affliction of your people, and send us swift aid in our time of necessity. Increase the fruits of the earth by your heavenly benediction; and grant that we, receiving your gifts with thankful hearts, may use them to your glory and the relief of those in need; through Jesus Christ our Lord. Amen.