What does it mean to have a "blessing"? Because we often think of blessing in a religious context, and because God is a character in the Torah, we might interpret a blessing to be of a spiritual nature. But looking at the word in the Torah in many different contexts, there is also a way to understand a blessing as a sense of stability and security.
In the mythic narrative of Torah, the first instances of the word being used are in reference to Creation: firstly for the animals, then for humans, and then for the day of Shabbat. In reference to the land in the context of Shmitah - the agricultural year of remission - the Torah's use of the language of blessing implies abundance as a result of long-term planning; and in the blessings that Moshe gives the people at the end of the Torah, and the juxtaposition of the dichotomy of blessing and curse, there is an implication of stability and security. When viewed together, many of the instances of the notion of blessing in the Torah might give us an understanding that when the Torah uses this language it alludes to the idea of a secure and nourished society that lives in a balanced equilibrium that supports sustainable Creation.
In Parashat Toldot the narrative has Yaakov and his mother Rivka working in consort to deceive Yitzhak, blind and believing himself to be dying, and conspire to have the blessing of the firstborn given to the younger Yaakov rather than his older twin, Esav. The blessing which Yitzhak gives directed toward Esav but received by Yaakov includes this phrase (Gen. 27:28):
וְיִֽתֶּן־לְךָ֙ הָאֱלֹהִ֔ים מִטַּל֙ הַשָּׁמַ֔יִם וּמִשְׁמַנֵּ֖י הָאָ֑רֶץ וְרֹ֥ב דָּגָ֖ן וְתִירֹֽשׁ׃
May God give you of the dew of the heavens and the fats of the earth; an abundance of new-grain and fresh-wine.
So much discussion over the generations has been had over the meaning of this verse. For my own personal interests, I tend to spend more time with commentaries that are geared towards a mystical, spiritual, or folkloric interpretation of the verse; however there are many commentaries that are focused on a simple, practical explanation of the Torah. One of those commentator, Rabbi Shmuel ben Meir, Rashbam (1085-1158, France), who also happens to be the grandson of the famous commentator Rashi, writes this on the verse:
That God should give you from the dew of the heavens, which is essentially the Blessing of the Field.
Rashbam does not explain this phrase, "blessing of the field," and it is not a phrase that is commonly used in Jewish literature despite Rashbam presenting it as if it is some kind of ubiquitous concept. However, in his commentary of the blessings which Moshe gives the people at the end of the Torah which I mentioned above, the 15th century Portuguese-Italian commentator and philosopher, Yitzhak Abarbanel, uses the phrase and he expresses an understanding the the "Blessing of the Field" is the state of productive relationship between farmers and soil, on the one hand, and shepherds and herd, on the other hand.
While not in the corpus of rabbinic literature, and a document translated into Hebrew from the original Greek, in his work "The Jewish Wars," Jewish-Roman historian Flavius Josephus writes (Jewish Wars 4:2):
There was only Gush-halav (Gischala) which had not been conquered by the Romans, it being a small city in the Galilee, its inhabitants were peaceful people, blessed in stewarding their land, and their soul's desire each day was simply the Blessing of the Field.
Seemingly, at least in the first century CE, the notion of the Blessing of the Field was the ability to safely and securely steward land without imposition or opposition.
The first blessing that Moshe gives at the end of the Torah is (Deut. 28:3):
בָּר֥וּךְ אַתָּ֖ה בָּעִ֑יר וּבָר֥וּךְ אַתָּ֖ה בַּשָּׂדֶֽה׃
May you be blessed in the city and may you be blessed in the field.
Experiencing the Blessing of the Field is about living in deep relationship with soil, with engaging in practices that ensure a stable and secure life for community across the spectrum. What we put into the land, both figuratively and literally, determines in so many ways what we harvest out of the land. This year of Shmitah, when the land is to rest and be released, provides the opportunity to invest in our relationship with the soil and with mystery.
We release and take a step back from the land to learn from her wisdom of rest how we best interact with our environments and our communities to meet the needs of individuals so that we can collectively build a society fundamentally grounded in the pursuit of equity and compassion. The stability and security possible from relating to the earth and our neighbors in this way could, to say the least, provide the abundant blessing the Torah mentions. The Blessing of the Field, then, is our ability to build community and equity such that our relationships are stable enough to as to ensure blessing for one another by working together.