193: Chapter 193 Compost Liquid Testing Imminent! Greenhouse Sees Steady Bumper Harvest

12:08 PM.

East side of the first floor of the Livestock Farm.

The Compost Fermentation Area is a twelve-square-meter isolated space, separated from the main area of the Livestock Farm by metal partitions.

Inside are two Sealed Fermentation Tanks with a one-ton capacity.

A thermometer is attached to the surface of the tanks, the needle pointing to 43.5 degrees.

Lin Wan squatted in front of the fermentation tanks, holding a temperature probe in her hand.

Liao Dacheng stood behind her, arms crossed over his chest.

"43.5," Lin Wan read out the number on the probe.

"It's 0.5 degrees higher than this morning."

"The temperature rise curve is normal." Lin Wan pulled out the probe, wiped it clean, and put it back into her tool bag. "At this rate, it'll reach 45 degrees by tomorrow morning."

"Once it reaches 45, open the valve."

"Yes." Lin Wan stood up and walked to the discharge valve on the side of the fermentation tank.

The valve is a metal ball valve with a ten-centimeter diameter, connected below to a PVC pipe that leads to a pre-installed interface on the wall.

The other end of the interface connects to the nutrient solution piping system of the third-floor Dome Greenhouse.

"Has this pipe been pressure tested?" Lin Wan asked.

"Ma Dong helped me test it yesterday afternoon. We poured twenty liters of fresh water in; it flowed out normally from the other end with no leaks."

"What's the length of the pipeline?"

"The total length from here to the Nutrient Solution Distribution Station in the third-floor Greenhouse is forty-two meters, passing through two elbows and a T-junction in between."

Lin Wan walked a few steps along the pipeline and touched the sealing ring at the interface with her hand.

"The sealing ring is new."

"Chief Engineer Han's people helped replace it; the original old ring had cracks."

"Good." Lin Wan turned to look at the two fermentation tanks. "Veterinarian Liao, confirm the raw material composition."

Liao Dacheng took a slip of paper from his pocket.

"Tank one: 400 kg of pig manure plus 80 kg of straw mulch and 120 kg of cow manure. Tank two: 300 kg of cow manure plus 60 kg of straw mulch and a small amount of poultry manure."

"What about the carbon-to-nitrogen ratio?"

"The first tank is around 25:1, and the second is at 28:1."

"25 to 28 is a bit high." Lin Wan stared at the paper. "The ideal range is 20 to 25:1."

"Too much straw mulch was added."

"For the next batch, reduce the straw by fifteen percent and add more cow manure. Cow manure has a low carbon-to-nitrogen ratio and can pull the overall ratio down."

"Okay, I'll take note of that."

Liao Dacheng flipped the paper over and wrote a few words on the back.

"Technician Lin, will the liquid coming out after opening the valve be poured directly into the nutrient solution pipeline?"

"Not directly," Lin Wan shook her head. "The resulting Compost Liquid needs to be filtered first to remove large particles and incompletely decomposed fibers. After filtration, it's diluted into the nutrient solution by ratio; the concentration cannot exceed five percent of the total liquid volume."

"Five percent."

"Yes, if the concentration is too high, it will burn the roots. For the first test, I plan to use three percent, to be conservative."

"Which set of Hydroponic Racks will we use for the test?"

"Set seven," Lin Wan said. "Set seven is planted with the edge area of the third crop of wheat; even if something goes wrong, the impact will be minimal."

"Is there a high probability of something going wrong?"

"Not really. The core components of Compost Liquid are ammoniacal nitrogen and fast-acting phosphorus and potassium, which are the same as chemical nutrient solutions, just from a different source. As long as the carbon-to-nitrogen ratio is normal, the fermentation temperature reaches the standard, and pathogens are killed, there isn't much difference from the effect of chemical nutrient solutions."

Liao Dacheng nodded.

"Then I'll notify you tomorrow morning once it reaches 45 degrees."

"Okay."

Lin Wan pressed her communicator.

"City Lord."

"Speak."

"The compost cycle inspection was completed at noon. The fermentation temperature is 43.5 degrees, and it's expected to reach 45 degrees tomorrow morning. Once it does, we'll open the valve for the first test, using set seven of the Hydroponic Racks for small-scale verification, with the Compost Liquid diluted to a three percent concentration."

"Are there any risks?"

"Low risk. If the test passes, we can expand it to all Hydroponic Racks in three days. The Greenhouse's nutrient solution consumption will then have a second source and will no longer rely entirely on chemical formulas."

"How much longer can the chemical nutrient solution inventory last?"

"Based on the consumption rate for the current ninety percent planting area, the chemical nutrient solution can last about forty-five days. Once the compost cycle is online, the consumption of chemical nutrient solution will be halved, so lasting ninety days won't be an issue."

"Ninety days."

"Yes."

"Good, let me know as soon as the test results are out."

"Okay."

The communicator disconnected.

Lin Wan walked out of the Compost Fermentation Area, through the main aisle of the Livestock Farm, past the Farrowing Room of ZM06, and looked down at the ten piglets.

They were all nursing.

Number Four was in the front position, its mouth around a teat, its small body rising and falling continuously.

Lin Wan walked toward the elevator.

The elevator doors opened, and a Welder in a work uniform stood inside, carrying a tool bag.

"Technician Lin," the Welder nodded.

"Were you sent by Chief Engineer Han to weld the support pillars of the Farrowing Room?"

"Yes, I'm Old Liu. The job is at 2:00 PM, but I came early to check the location."

"Veterinarian Liao is inside."

"Okay."

The Welder walked toward the Livestock Farm.

Lin Wan entered the elevator and pressed the button for the third floor.

The Full-spectrum LED Lights in the Greenhouse were running at full power.

The seeds for the third crop of Fast-growing Wheat were sown yesterday morning, and dense white roots could already be seen on the Hydroponic Racks.

Ninety percent coverage.

In the 14,000-square-meter Greenhouse, 12,600 square meters were all wheat.

Harvesting in seven days.

Day 67.

She walked to the Strawberry area.

The fruit bodies of the second batch of eight Strawberry plants continued to swell; the plumpest one was already four and a half centimeters, and the red at the top was a shade deeper than yesterday.

Maturing between Day 64 and Day 66.

At the same time as the third wheat harvest.

It will be very busy during those days.

Lin Wan squatted down to check the nutrient solution flow rate at the roots of the strawberries; it was normal.

She stood up and looked at the three modified Watermelons in the corner of the Greenhouse.

They were as big as two fists.

Still growing.