Viral infection can reduce the net nitrogen inputs of legume break crops and cover crops

Abstract

Legumes are used in crop rotations by both large‐scale and smallholder farmers alike to increase soil fertility, especially before high‐nitrogen‐demanding crops such as corn (maize). Legume crop residues and green manures are rich in nitrogen due to mutualistic rhizobia, bacteria that live in their roots and convert atmospheric nitrogen into a biologically available form. Growers can obtain recommendations from local extension offices about how much less inorganic nitrogen fertilizer needs to be added to a subsequent crop following different legume break crops for the predominant soil type (the nitrogen fertilizer replacement value, or NFRV). Due to the intimate relationship between legumes and rhizobia, conditions that affect plant health can also affect the rhizobia and how much nitrogen they provide. We use a combination of empirical data and previously published values to estimate reductions in nitrogen inputs under outbreaks of plant viruses of varying severity. We also use historical fertilizer prices to examine the economic impacts of this lost fertilizer for farmers. We find that fertilizer losses are greatest for crops that fix large amounts of nitrogen, such as clover and alfalfa as opposed to common bean. The economic impact on farmers is controlled by the proportion of plants with viral infections and the price of synthetic fertilizer. In a year of high disease prevalence, attention is normally focused on the yield of the diseased crops. We suggest that farmers growing legumes as break crops should be concerned about yields of subsequent crops as well. Viral diseases can be difficult to diagnose in the field, so the easiest way for farmers to prevent unexpected yield losses in subsequent crops is to test their soil when it is feasible to do so.

Reciprocal plant‐mediated antagonism between a legume plant virus and soil rhizobia

“…For example, in legume crops, PEMV outbreaks occur early in the growing season (Clement et al, 2010). In other studies, infection of legume crops with viruses has been shown to reduce nitrogen inputs to soil by interfering with legume-rhizobia symbiosis (Marchetto & Power, 2021). Our study shows PEMV may similarly reduce nitrogen provided by rhizobia to soil.…”

Application of Asymmetric Catalysis in Chiral Pesticide Active Molecule Synthesis

“…Besides plant bacteria, the plant virus diseases can also inflict severe damage on a wide range of crops worldwide, which is often likened to “plant cancer” due to their devastating impact and challenging control. , As three of the most serious plant viruses, tobacco mosaic virus (TMV), potato virus Y (PVY) and cucumber mosaic virus (CMV) can infect a great number of plant species and result in significant losses in both global economy and agricultural production . Although the application of antiviral agents has been proven to be one class of the efficient strategies for preventing and controlling plant virus diseases, , while the commercial antiviral agents are still limited.…”

Recent Achievements in Antiviral Agent Development for Plant Protection

“…Plant virus diseases have caused significant damage on rice, tobacco, pepper, and other crops all over the world. − It is recognized as the cancer of plants and frequently causes severe global economic losses . According to the statistics, the most serious plant viruses in the world include tobacco mosaic virus (TMV), tomato spotted wilt virus (TSWV), tomato yellow leaf curl virus (TYLCV), cucumber mosaic virus (CMV), potato virus Y (PVY), and so on .…”