. China does not control "most" of the USA's debt

Top Ten US Debt Holders
Japan $712B
China $194B + Hong Kong $53B = $247B
UK $164B
"Caribbean Banking Centers" $69B
South Korea $69B
OPEC $60B
Taiwan $59B
Germany $54B
Switzerland $40B

As to agricultural output, we are still the breadbasket of the world,
and I can cite statistics, though that's pretty lame.

China's population is expected to grow from 1.3B to 1.4B in 20 years.
That is 100,000,000 more mouths to feed from a land mass of which is
only 10% arable and declining rapidly from desertification.

Agriculture in the US will be looking mighty good in about 10-15 years.