Emerging from Madam Xu's residence, Xie Jiang followed Xu Hengyan directly to his courtyard.
Xu Hengyi, of course, tagged along. He was Xie Jiang's little follower, naturally going wherever Xie Jiang went.
Guang Bai served the three of them tea and snacks before retreating to a corner.
Xie Jiang looked at the sweet potatoes placed on the table, two of them freshly cooked and steaming. "Sweet potatoes are best when roasted," he commented.
Xu Hengyan, unable to wait, inquired, "To my knowledge, our Dayu has never cultivated sweet potatoes. May I ask where you, Master Xie, procured them?"
"Oh, Dayu doesn't have sweet potatoes? I thought perhaps you nobles in the Duke's manor were unfamiliar with basic grains."
"I've investigated specifically. Dayu truly has no sweet potatoes, and even the officials at the Ministry of Agriculture have never heard of them."
Xie Jiang gave an "oh" and picked up a dried sweet potato from a plate on the table, chewing it slowly. "These sweet potatoes are also called gan shu or fan shu. They're not a rare commodity in our Lan Yong. Ordinary farming households plant some for supplementary food."
"Lan Yong?" Xu Hengyi found the name somewhat familiar, but it didn't seem to be in their Dayu kingdom.
"Nanyang?" Xu Hengyan clearly knew.
Upon hearing this, Xu Hengyi's eyes lit up. He looked excitedly at Xie Jiang. "Are you from Nanyang? Is your home in Lan Yong? I knew it! No wonder you're different from us in every way, even your tastes are different. So you're from Lan Yong!"
That made sense. After all, he was a foreigner. "Do you have to take a boat to Nanyang? Is it very far? How long does it take to travel by boat from Lan Yong to our Dayu?"
He wasn't particularly interested in sweet potatoes, but he had never been out to sea. In his eyes, Nanyang was as distant as the horizon, let alone Lan Yong.
"Besides your Lan Yong, how many other countries are there in Nanyang?"
Xu Hengyan, whose conversation had been interrupted, glanced at him.
Xu Hengyi immediately fell silent. He understood, he understood. He wouldn't ask anymore.
"My ancestors were also from Dayu, but they later settled in Lan Yong. If you're interested in Nanyang, when I return in the future, I'll take you out to sea for some fun."
Xu Hengyi nodded enthusiastically, feeling that his days of following Xie Jiang hadn't been in vain. However, looking at Xu Hengyan before him, he suppressed the cheers that were about to burst out.
"I like eating roasted sweet potatoes and sweet potato starch. My servants always carry some wherever we go. We've been in Dayu for the past two years, and they've probably planted some themselves. This thing grows easily with just a little cultivation."
Xu Hengyan couldn't help but be intrigued. "Are there any special requirements for the environment and soil? What's the approximate yield?"
Xie Jiang toyed with the dried sweet potato between his fingers. "There are no special requirements. As far as I know, it's suitable for almost any land. Just toss a vine on the ground, and it can yield a large basket. The yield is surprisingly high, several dozen times that of rice. But who would eat this every day? You haven't eaten it before, so you find it novel. If you were to eat sweet potatoes every meal, you'd want to vomit within three days..."
Xu Hengyan was shocked. "Several dozen times?"
Even if Xie Jiang was exaggerating, and it wasn't several dozen times, but even ten-odd times after drying, it would be incredible.
It didn't even need ten times. If it could yield three to five times more than rice, that would be remarkable.
And it wasn't picky about the land!
Xu Hengyan thought of those barren lands, and his breathing involuntarily quickened.
"Yes, this thing has a very high yield. The per-mu yield is about..."
Sweet potatoes could easily yield five to six thousand catties per mu. It was said that high-yield varieties could reach ten thousand catties.
However, considering the average grain yield of this era, Xie Jiang feared they wouldn't believe him if he said too much.
"Just planting it casually, it's three to four thousand catties, at least."
Xu Hengyan gasped. "Per mu?"