The above photo shows a meeting at the village of Espino on the Honduran border between Guardia Nacional de Nicaragua troops led by Col. Robert L. Denig and Honduran Army General Alejandro Plata.  Espino lay on the road from Somoto in the Western Segovias to San Marcos de Colón in southern Honduras.  The GN troops are seated and hlding new Browning Automatic Rifles and Krags; the Honduran troops are standing; some are armed with rifles and/or machetes.  The date was August 7, 1930, according to the "Personal Diary" of Colonel Denig, also housed on this website under "USMC-DOCS" (vol. 2, p. 142). 

The caption on the rear reads:

     "Espino, Honduras (side)
     Colonel Denig, G.N.
     General Plata
     Guardia sitting
     Honduraians standing"

There is also a purple stamp that says, "MARINE POST STUDIO, CAMPO DE MARTE, MANAGUA, NICARAGUA" and a handwritten "#10".  As can be seen in the detail below, the photo is a bit blurry, even after scanning it in high-resolution (600 dpi):

Here is the caption on the rear:

Here is Colonel Denig's description of the event from his personal diary, marked by his usual deadpan sense of humor; click on thumbnail at right for a JPEG image of the original:

DIARY OF A GUARDIA OFFICER

7 August 1930.

   "Reinforced by Gregon Williams and his patrol, we cleared Somoto at 7:00 for Espino, where we arrived at 10:45. Beautiful ride, near the end of which we went through the gorge of the upper Coco, much like Watkins Glen N.Y., on a larger scale. Then up and up, to Espino which is on the edge of a cliff about 5000 feet in elevation from which you can see nearly all of Segovia. As we approached Espino we heard bugles and looking toward the sound, that came from a mountain top, we saw the red-white-red flag of Honduras. We then displayed our blue-white-blue one. At Espino some ten miserable shacks on the border, in Honduras, we were met by General Plata and his staff. We had a conference on the bandit question over a banquet of coffee, cheese, coffee, tortillas, coffee, sardines, coffee and beans.
   "The Honduran troops, 30 in number, had big heavy rifles and machettes and an assortment of uniforms from Hungarian Huzzar to just plain mozo. None had shoes, some had sandals, all had their toes stubbed from the rocks. Back to Somoto, latter part of the ride in heavy rains. Distance covered 30 miles. . . ."

Photograph has no caption, but General Elias Root Beadle is easily recognizable from other photos.  According to the official website of the US Marine Corps, in Nicaragua General Beadle "formed, trained and commanded the Guardia Nacional and oversaw the elections of 1928. He received high praise for his work in Nicaragua and received the Navy Cross for his services. Beadle retired from the Marines as a lieutenant colonel in March 1930. He died Nov. 18, 1946." (Source:  https://www.mcrdpi.marines.mil/Centennial-Celebration/Historical-information/7-First-Commander-of-Recruit-Training/)

I suspect this grisly photo was taken in the aftermath of the Battle of Chinandega in February 1927 during the 1926-1927 Civil War, when much of the city was reduced to rubble.

Close inspection of this photo reveals dozens of buzzards (zopilotes) hovering over and around the remains of what are probably burned human cadavers.  A black-and-white dog is also partly visible among the cluster of buzzards at left.  Just right of center, another big group of buzzards can be seen in the open space behind the piles of smashed clay roof tiles in the foreground.  Another group sits on the roof of the small outbuildig at left. The photograph suggests that many human remains lie around and buried beneath the rubble.