Field Crop 2025, Vol.8, No.3, 126-138 http://cropscipublisher.com/index.php/fc 134 frequent, it is suitable to grow soybeans such as Si Li Hong and Sui Nong 28, and peas like Qinghai 13 can be chosen. In the semi-humid and slightly arid area in the northern part of the Huanghuai region, the annual rainfall is 500 to 600 millimeters, but it is prone to drought in summer and autumn. For soybeans, Handou 13 and Shengyu 6 are recommended. For peanuts, HO-1 can be chosen. For mung beans, early-maturing types such as "Jingyan 7" are suitable. In the more arid Hexi Corridor and the Northwest Plateau, the annual rainfall is less than 250 millimeters. It is recommended to plant mung beans "Longlv No.1" and peas "Ningwan No.1". Peanuts carry a high risk, so it is necessary to choose small-sized early-maturing varieties such as "Huayu 28" (Zhang et al., 2011). In addition, crop rotation or intercropping (such as peas/millet) can help retain moisture and increase production. Combining 2 to 3 complementary varieties in the same area can also reduce risks. In conclusion, it is very necessary to precisely recommend varieties based on local characteristics. 7.2 Optimization measures for field management Although drought-resistant varieties are important, if they are not managed properly, their effectiveness will also be compromised. In terms of moisture retention, mulching or minimal no-tillage is often better than bare land, and the soil moisture content during the seedling stage can be 2%-5% higher. The density is not constant. In dry years, it is appropriate to reduce it by 10%-15%. For instance, if the yield of soybeans is reduced from 330 000 plants per hectare to 280 000 plants, the yield per plant can still increase. When there is more rain, the plants can be planted more densely. Fertilization depends on the situation. During drought, potassium and boron fertilizers can help maintain water balance. Spraying some potassium dihydrogen phosphate and micro-fertilizer on peas during the flowering period can increase production by approximately 8%. In some places, water is stored through rainwater collection ditches and small plots for planting. Even in extremely dry years, some water is replenished to prevent "neck drought". Intercropping is also quite interesting. For instance, when soybeans and corn are interplanted in strips, water can be utilized more fully. The sowing period can also be adjusted. If summer soybeans are sown earlier or mung beans are sown at different times, the summer drought can be avoided. Some varieties have their own "exclusive combinations". For instance, HO-1 peanuts are suitable for ridging and mulching, while Qinghai No. 13 peas have the best topdressing effect during the flowering period. Ultimately, whether drought resistance potential can be fully exploited depends not only on the variety but also on keeping up with management measures. 7.3 Development of drought-tolerant breeding strategies and methodologies This research has provided some ideas for drought-resistant breeding to some extent. Yield is of course important, but focusing solely on it is not enough. Factors such as whether the root system is deep enough, whether it can retain water, and the efficiency of water use all need to be taken into consideration. In fact, initial screening can be conducted during the seedling stage or even in greenhouse conditions, such as observing the root morphology, proline accumulation or whether the leaves remain green, and then determining the target based on different ecological zones. Molecular technology is now becoming increasingly practical. Whole-genome scanning can identify QTLS and markers, accelerating the process. Gene editing can also directly replicate known drought-resistant variations. However, traditional methods should not be abandoned either. It is more reliable to use them in combination. High-throughput methods can also be put to use. Remote sensing and thermal imaging can both quickly assess the drought resistance level of large groups. Models like CROPGRO can also simulate the performance of varieties in specific environments, which is very helpful for arranging experiments. The "old tricks" such as deep root systems and early maturity to avoid drought are still effective, but now we still have to deal with the superimposed situation of high temperatures and drought, and the requirements for compound stress resistance are even higher (Figure 2) (Wu et al., 2024). If there is truly policy support and molecular design becomes increasingly mature, the breeding cycle is expected to be shortened, and drought-resistant and high-yield varieties will have a greater chance of being truly implemented in agriculture in arid areas. 8 Limitations and Future Research Directions This time, we evaluated a batch of drought-tolerant legume varieties under rain-fed conditions. Although some discoveries were made, there were also many limitations. For instance, the experiment only covered three pilot areas in the north. Areas like the karst regions in Southwest China or the winter and spring arid regions in the
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