I'm happy to report that Farmer Mac has been successfully operating uninterrupted with 100% of our employees working remotely, and we've been doing that since March 12.
We provided $1.3 billion of new credit to rural America that ultimately is to people in the first quarter of 2020.
We have remained well capitalized with a strong liquidity position that has been at or above $1 billion for most of the last couple of months.
As we have previously noted, we indefinitely suspended our $10 million share repurchase program in early March to preserve capital and liquidity and as additional precautionary measure.
More specifically, we have approved 71 payment deferment requests related to COVID-19 through May 1 with a total principal balance of $78.9 million.
That's less than 0.5% of outstanding credit.
Now, turning to business volume, 2020 is off to a good start for Farmer Mac, as all four lines of business contributed to net outstanding business volume growth of $421.4 million this quarter.
This reflects loan purchase net volume growth in Farm & Ranch, USDA and Rural Utilities of a combined $303.3 million, which was partially offset by a sequential decrease in net growth in long-term standby purchase commitments and guaranteed securities of $137.8 million.
We also saw increases in institutional credits, which grew $255.9 million, largely driven by our ability to provide short-term liquidity for two of our largest counterparties during the most volatile capital markets environment during the month of March.
In our Rural Utilities lines of business, loan purchase net volume grew $118.4 million in the first quarter of 2020 compared to $490.3 million in the same period last year.
It is important to note that loan purchase net volume growth in the first quarter of 2019 included one large unique transaction, the purchase of a $546.2 million portfolio of participations in seasoned Rural Utilities loans from CoBank.
Loan purchase net volume growth in our foundational Farm & Ranch and USDA lines of business was $184.9 million for the first quarter of 2020 versus a net volume decline of $64.7 million for the same quarter in 2019.
Farm & Ranch loan purchases had net volume growth of $142.1 million during the quarter, overcoming one of our largest prepayment quarters of over $260 million, primarily related to the January 1 payment date, as well as increased scheduled principal amortization levels, given our larger portfolio.
Approximately 40 animal protein processing plants have temporarily closed for parts of March and April and over 40% of hog and 30% of cattle processing was offline in early May.
Ethanol typically consumes between 30% and 40% of annual US corn production.
Agricultural exports through March were down from 2019 levels, driven by a 15% drop in corn and soybean sales.
In April, USDA announced $16 billion in direct emergency aid, targeting cattle, dairy, hog, specialty crop and grain producers, and an additional $3 billion in food purchases for donation and distribution.
Additionally, the CARES Act signed in March authorized a $14 billion replenishment of the Commodity Credit Corporation for possible direct farm and ranch aid later this year.
According to data released by the SBA, the first round of Paycheck Protection Program payments delivered nearly $3 billion to small businesses involved in agriculture, forestry, fishing and hunting.
The Farm & Ranch portfolio has no direct credit exposure to hog or cattle processing facilities, and only $40 million or 0.5% in hog production and only $21 million or 0.3% in dairy processing as of March 31.
We do have exposure to several indirectly affected commodities like corn and soybeans at $2.4 billion or 30% of the Farm & Ranch portfolio, ranch cattle and calves at $672 million or 9% of the portfolio and dairy at $538 million or 7% of the portfolio as of March 31.
For example, the corn and soybean portfolio is spread across more than 5,000 loans in 601 counties in 41 states.
Loans past due by 90 days or more increased in the first quarter of 2020 to 1.02% of the outstanding Farm & Ranch portfolio or 0.37% across all four lines of business.
Individual loan risk ratings held steady in the first quarter of 2020, with substandard loans totaling $317 million across all loans and guarantees.
This volume is spread across 56 commodities in 212 counties in 36 states.
In fact, one of them was the longest GSE SOFR issuance and $285 million in structures, 10 years of greater, with total medium-term note issuances of approximately $2.5 billion to date.
Our strong liquidity position, as Brad mentioned, and market access also enabled Farmer Mac to call higher-cost issuances, provide funding to business lines for new assets and add over $160 million in high-quality liquid assets to our investment portfolio.
Core earnings were $20.1 million for first quarter 2020 compared to $22.2 million in first quarter 2019.
Net effective spread was $44.2 million in first quarter 2020 compared to $38.8 million in the same period last year.
Net effective spread in percentage terms remained stable at 89 basis points for both periods.
The $2.1 million year-over-year decrease, though, in core earnings was primarily due to a $3.3 million after-tax increase in the total provision for losses and a $2.7 million after-tax increase in operating expenses.
Of the $3.8 million loss provision during the first quarter, approximately $3.5 million was attributable to factors related to COVID-19.
Operating expenses increased by 26% in first quarter 2020 compared to first quarter 2019.
As of March 31, 2020, total allowance for losses were $19.1 million, an increase of $6.5 million from December 31, 2019.
The total allowance for losses represents 9 basis points of Farmer Mac's $21.5 billion portfolio, and we continue to compare very favorably to industry peers.
It is therefore important to note that as of March 31, 2020, Farmer Mac's $2.4 billion in outstanding Rural Utilities loan purchases and long-term standby purchase commitments have no historic or current delinquencies.
Farmer Mac's $815.1 million of core capital as of March 31, 2020 exceeded our statutory requirement by $165.8 million or 25%.
This compares to $815.4 million of core capital as of December 31, 2019, which exceeded our statutory requirement by $196.7 million or 32%.
However, from an overall liquidity standpoint, we are comfortable with our current cash position, which is hovering around $1 billion and which was at $1.2 billion on March 31, 2020.
This level resulted in 202 days of liquidity and it's far exceeded our regulatory requirements by approximately 112 days.
April, likewise, continued to be strong with a daily average cash position also around $1 billion, accompanied by strong levels of liquidity, which have continued through today.

Summary:
We provided $1.3 billion of new credit to rural America that ultimately is to people in the first quarter of 2020.