Doomsday Bunker Upgrade

　　Qin Lan brought a lot of materials on the list, but these materials need to be exchanged by Chen Xin with the vegetables produced in his refuge. The list also lists the exchange ratio that the SWAT team deems appropriate after discussion.

　　 Of course, Chen Xin has no objection to the exchange of materials, which is also very good for him, but he has different opinions on the proportion of material exchanges.

"One hundred catties of fresh vegetables are exchanged for five bags of cement? This ratio is acceptable." Chen Xin looked at the exchange ratio marked on the list, checking one by one: "But the steel bar is a bit exaggerated, isn't it? Twenty catties of vegetables can be used. Change a steel bar?"

　　 Steel bars are extremely useful for Chen Xin. Apart from anything else, reinforced concrete must be used to reinforce the door of the shelter.

　　 "What we provide is standard φ12X12 steel bars, and you know that there are no steel plants in this city. All of these rely on railway input, and the price is understandable." Qin Lan explained to Chen Xin.

　　 Although the two used to be boy and girl friends, they obviously did not hesitate their past feelings when they were bargaining.

"But only twenty catties of vegetables can be exchanged for a steel bar. The price is still outrageous. I think ten catties is an acceptable price." Chen Xin opened the mouth and cut the exchange rate in half, but looked at Qin Lan. Waiting for her to bargain.

　　 As expected, Qin Lan shook her head and refused directly: "Ten Jin is too little, at most 18 Jin."

　　 However, Chen Xin refused to give up, still repeating: "Ten Jin, or I will find someone else to change it."

"This is impossible. Even if you put it before the disaster, you can't exchange ten catties of cabbage for a steel bar." Qin Lan shook her head vigorously, but made a compromise: "Fifteen catties, no less. "

　　 Hearing Qin Lan's words, Chen Xin laughed and said to her: "One step back, twelve catties, let me get fifty steel bars first. I need them urgently."

　　 "Need urgently? What are you going to do, Axin? Need so much steel?" Qin Lan suddenly became curious when he heard Chen Xin's urgent need.

Chen Xin said directly: "The end of the world has been coming for three months, and the temperature is almost close to freezing. Before freezing, I plan to reinforce the door of the refuge. So in addition to steel bars, cement, sand and steel plates are needed. , I can accept the exchange ratio of these building materials, so let's ship them together as soon as possible."

　　 Hearing Chen Xin said that it would be used to reinforce the door of the refuge, Qin Lan nodded clearly, and agreed very happily.

At present, the official shelters are also undergoing large-scale expansion work. All shelters have been allocated a large amount of construction materials. The amount of materials required by Chen Xin is not large. The SWAT team only needs to allocate a little from its own materials. Able to meet his needs.

After discussing the demand for construction materials, Chen Xin put forward a demand that was not on the list: "Alan, can you help me get some glass? It's best to be a large glass tube like a cylinder. An aquarium with this shape is even better, and there is also a vacuum pump."

　　 "You can get it, but Axin what do you want these things?" Qin Lan asked strangely.

Chen Xin smiled and explained: "The aquarium can be transformed into the suggested algae oxygen generator. Living in an underground shelter will definitely have oxygen problems. I need one myself, and Dragon Mother also needs one. I can help her make one. You can exchange all the good wine in her place. Drinking in cold weather can keep you warm."

　　 "You're not a Maozi, why don't you drink to keep warm!" Although Qin Lan complained like this, she still agreed to Chen Xin's request and wrote down what Chen Xin wanted in her portable notebook.

　　 The two again checked the exchange ratios of the various materials on the list, as well as the items outside the order that Chen Xin added, and this ended the bargaining between the two.

　　 After the bargaining was over, the topic between the three became much easier, and Chen Xin also asked about some topics that interest him.

　　 "Speaking of which is the main food in the refuge now? Isn't it really mouse, earthworm and mushroom soup?" Chen Xin joked.

　　 But rats, earthworms and mushrooms are indeed all animals and plants suitable for raising in low temperature and underground without light, and they are also the main food sources of refuges announced by the state before the disaster.

In response to this question, Ding Ning just shrugged and leaned on the sofa in Chen Xin’s living room: “I just evacuated the shelter recently. It’s not very clear, but what I ate is basically rat meat stewed with potatoes and mushrooms. It's weird to be able to manage."

“The country has mobilized a lot of rice before the disaster. It’s not strange to have rice to eat now.” Qin Lan knows a little bit better than Ding Ning, so she explained to Chen Xin: “As for mushrooms and potatoes, mushrooms are currently every refuge. For all the things that are being grown, the yield of mushroom bags provided by the state is good, and now it can be harvested once a month. If the planting area is not enough, mushrooms alone can already meet the food needs."

　　 Speaking of this, Qin Lan paused before continuing: "As for potatoes, the country does not promote large-scale cultivation of potatoes. Although these things are high-yielding, the demand for soil and fertilizer is also high, which is not as stable as mushrooms.

　　 It also consumes water and electricity, and the general refuge does not have the conditions for large-scale planting. Therefore, the city has opened a special underground planting area near the power plant to grow potatoes, and the output is not too high. "

　　 Chen Xin nodded in understanding when Qin Lan said this.

　　 In fact, when he built the shelter, the first thing he thought of was planting potatoes.

　　 Thanks to the blessing of the "Martian Rescue" that year, everyone knows that planting potatoes can survive, so I feel that the end times are now. Shouldn't you plant potatoes at this time?

　　 Especially in various traversing novels, in addition to burning glass to make soap through ancient times, finding potatoes has almost become a must-do.

　　 It seems that everyone thinks this is a kind of fetish. The yield of several thousand catties per mu of crops is undoubtedly a dimensionality reduction blow for traditional agriculture that may be less than one-tenth of the yield of potatoes.

　　Potatoes do have many advantages. First of all, the yield is naturally high. A few thousand catties per mu seems to be a normal yield for potatoes.

Secondly, potatoes are very suitable for growing in alpine regions. Mongolia in the Yan country and Siberia in Lucia are the main production areas for growing potatoes. They can still grow healthily in an environment where the temperature is only 10 degrees or less, without too much water. Irrigation can guarantee a higher yield.

　　Moreover, potatoes are also nutritious and rich in starch. They can provide a lot of calories and nutrients to the human body in a cold environment. They are indeed important foods for life.

　　 But potatoes are not perfect.